Remove dead code from the FFI shim layer, link_interface tables, jssink/jest codegen, and REPL shims - #37788

… and misc crates (#39574)

### Problem
- `src/jsc/bindings/libuv/` is only on the include path for non-Windows
builds (`scripts/build/flags.ts`, "libuv stubs for unix"). `uv/win.h`
(703 lines) and `uv/tree.h` (512 lines, included only by `win.h`) are
never reached.
- `uv/sunos.h`, `uv/os390.h`, `uv/aix.h` and `uv/posix.h` are selected
by `uv/unix.h` only on Solaris, z/OS, AIX, IBM i, Cygwin, Haiku, QNX and
Hurd. Bun builds for linux, macOS and FreeBSD.
- `packages/bun-error` is embedded in the dev error page
(`src/runtime/server/dev-error-page.html`). The page calls the function
behind `Symbol.for("Bun__renderFallbackError")` and nothing else.
`renderRuntimeError`, the abort state `dismissError` kept for it, and
the two modules only it imported (`sourcemap.ts`,
`stack-trace-parser.ts`) have no callers. #37081 lists this path as a
follow-up.
- `bun_zlib_sys::posix` and `bun_zlib_sys::win32` declare zlib functions
that nothing calls. `bun_zlib` declares its own. The only use of the two
modules was as re-exports of the types in `shared.rs`.
- A set of `pub` items in other crates has no user in any crate. rustc
cannot report them because `pub` items count as used.

### Fix
- Delete the six libuv headers. `uv.h` now includes `uv/unix.h`
directly. `uv/unix.h` keeps the linux, darwin and BSD branches.
`uv-posix-polyfills.c` drops the commented-out copies of the removed
branches.
- Delete `renderRuntimeError`, `sourcemap.ts` and
`stack-trace-parser.ts`. `dismissError` keeps the part that removes the
overlay. `runtime-error.ts` stays (it has a test).
- Delete `bun_zlib_sys/posix.rs` and `win32.rs`. `bun_zlib` imports the
types from `bun_zlib_sys::shared`, which is where the removed modules
took them from.
- Delete the unused Rust items listed below, plus the trait
implementations and imports that only they needed.

Verification:
- Every Rust item was found by making the unexported items crate-private
and compiling the workspace. An item is deleted only if rustc reports it
dead on x86_64 linux (dev, release, and with the `bun_debug` and
`bun_asan` cfgs), aarch64 linux, x86_64 musl, x86_64 Windows and aarch64
macOS.
- Each removed name was also searched in `src/codegen/`, the
`*.classes.ts` files, `src/js/` and the C++ bindings. Items that a
codegen template can emit were kept.
- `bun run rust:check-all`: 12 of 12 targets pass. `cargo check
--workspace --all-targets` passes (benches and unit tests still
compile). `cargo check -p bun_shim_impl --features shim_standalone` for
the Windows target passes.
- `bun bd` builds. The build recompiles `uv-posix-stubs.c` and
`uv-posix-polyfills.c` against the trimmed `uv.h`, and rebuilds the
bun-error bundle, which no longer exports `renderRuntimeError`.
- New test in `test/js/bun/http/serve.test.ts`: it takes the bun-error
bundle out of a real 500 page, evaluates it outside a browser, and
checks that the bundle registers the renderer and that `dismissError` is
a no-op when nothing is rendered. This is the surface the
`packages/bun-error` change touches.
- `bun bd test` passes for `test/js/bun/http/serve.test.ts -t "dev error
page"` (including the new test), `test/js/bun/runtime-error.test.ts`,
`test/js/bun/util/{zstd,arraybuffersink,filesink}.test.ts`,
`test/js/node/zlib/deflate-streaming.test.ts`,
`test/js/web/encoding/text-{encoder,decoder}.test.*`,
`test/js/workerd/html-rewriter.test.js`,
`test/js/bun/css/nth-anplusb-ident.test.ts`,
`test/js/web/fetch/blob.test.ts` and
`test/internal/source-lints/dead-code-escapes.test.ts`.
- `cargo fmt --check`, clang-format on the touched C file and prettier
on the touched TypeScript files pass.

<details>
<summary>Removed Rust items</summary>

- `bun_zlib_sys`: modules `posix` and `win32` (`struct_gz_header_s`,
`gz_header`, `gz_headerp`, `in_func`, `out_func`, and the `deflate*`,
`inflate*`, `compress*`, `uncompress`, `adler32`, `crc32`, `zlibVersion`
declarations), `shared::voidpf`.
- `bun_zlib`: declarations `compress`, `compressBound`, `uncompress`,
and the `internal` module that selected between the two removed modules.
- `bun_zstd`: `decompress` (every caller uses `decompress_append`).
- `bun_libdeflate_sys`: `libdeflate_deflate_decompress` (the `_ex`
variant is the one in use).
- `bun_mimalloc_sys`: `mi_strdup`, `mi_heap_collect`,
`mi_thread_set_in_threadpool`.
- `bun_cares_sys`: `ares_strerror`.
- `bun_windows_sys`: `SetHandleInformation`, `closesocket`.
- `bun_alloc`: `default_alloc::calloc`.
- `bun_core`: `GenericIndexInt::from_usize` and its macro-generated
implementations.
- `bun_css`: the four deprecated `to_css` methods on
`GenericSelectorList`, `GenericSelector`, `GenericComponent` and
`Combinator`. Their bodies were `unreachable!()`; the serializer
functions replaced them.
- `bun_runtime`: `JsSinkType::done` and its six overrides,
`FileCloser::update` and its implementations, `ReadableStream::to_js`,
`node_fs::Null::to_js`.

</details>

<details>
<summary>Overlap with open pull requests</summary>

The deletions here were checked against the open dead-code pull requests
(#35437, #35775, #35880, #36115, #36237, #37012, #37149, #37181, #37208,
#37301, #37454, #37659, #37788, #38005, #38900, #39319, #39561) and
against #38958 and #35075. Nothing deleted here is deleted by any of
them. Candidates they already cover were left out: `src/jsc/bindgen.rs`
(#37149), the dead `pub use` re-exports (#39319), the simdutf big-endian
and UTF-32 wrappers (#38958), and the items named in the skip lists of
the others. Some files here (`bun_alloc/lib.rs`, `bun_core/util.rs`,
`libdeflate.rs`, `mimalloc.rs`, `node_fs.rs`, `Blob.rs`, `FileSink.rs`,
`ReadableStream.rs`, `streams.rs`, `windows_sys/externs.rs`) are also
touched by open pull requests in different hunks. #36437 edits
`packages/bun-error` from a base that predates #37081; it changes one
import line in `stack-trace-parser.ts` and keeps `renderRuntimeError`,
so it does not overlap with this deletion but will need a rebase.

</details>

<details>
<summary>Found but not deleted (judgment calls for a
maintainer)</summary>

- `packages/bun-inspector-protocol/src/protocol/v8/` (about 32,600
lines): not exported by the package index since 2023 and regenerated
only with the opt-in `--v8` flag of `scripts/generate-protocol.ts`.
#39110 kept the flag, so this needs a decision.
- `packages/h3blast` (1,468 lines) and `packages/bun-build-mdx-rs` (558
lines): nothing in the repository references them. They may be kept on
purpose as a load generator and a proof of concept.
- `packages/bun-error/runtime-error.ts` is unused by the page but
covered by `test/js/bun/runtime-error.test.ts`. The four images in
`packages/bun-error/img/` are referenced only by the source glob in
`scripts/glob-sources.ts`.
- `HotReloadTaskView` in `src/jsc/hot_reloader.rs`: both `reload`
implementations ignore the task, and `VirtualMachine::reload` ignores
its `Option<HotReloadTask>` argument. Removing the plumbing is a small
refactor rather than a deletion.
- `react_compiler/compile_result.rs` has constructors and fields with no
users, but the file says the types are waiting to be wired up.
- The streams-era private globals in `BunBuiltinNames.h`
(`makeGetterTypeError`, `makeDOMException`, `addAbortAlgorithmToSignal`,
`removeAbortAlgorithmFromSignal`, `isAbortSignal`,
`createUninitializedArrayBuffer`, about 100 lines of
`ZigGlobalObject.cpp`) have no JS callers. Both files are being edited
by several open dead-code pull requests, so they were left for a later
run.

</details>

### Background
- rustc's `dead_code` lint treats every `pub` item in a library crate as
used, because another crate could import it. In this workspace every
crate is an implementation detail of one binary, so a `pub` item with no
importer in any crate is dead in the same sense as a private one. Making
such items crate-private for one compile lets rustc report the ones with
no users at all. The visibility changes themselves are not part of this
pull request.
- On POSIX, bun does not link libuv. Node-API addons that reference
libuv symbols get `uv-posix-stubs.c` and `uv-posix-polyfills*.c`, which
are compiled against the copied headers in `src/jsc/bindings/libuv/`. On
Windows the real libuv is linked and that directory is not used.
- `JsSinkType` is the Rust trait behind the native sink classes
(`FileSink`, `ArrayBufferSink`, the HTTP response sinks). Its methods
are called from the shared sink glue in `Sink.rs`; `done` was declared
there but the glue never called it.

<!-- robobun:evidence:begin -->

---

**no test proof** · iteration 1 · Platform-specific test(s) that do not
run on this machine. Deferring to CI, which covers all platforms:
test/js/bun/http/serve.test.ts

<!-- robobun:evidence:end -->

…ockets, and the builtin-name tables (#38900)

Removes 775 lines that nothing references (8 lines of signature, import
and comment adjustments added), across node:http2, the HTTP/2 frame
parser, the JSC/WebCore bindings, uSockets, four Rust crates, the
builtin-name tables and scripts/. No behavior change. A 153-line source
lint pins every removed symbol.

### Problem
- `src/js/node/http2.ts` binds every entry of `constants` as a local
(`const { ... } = constants;`); 178 of the 240 bindings have been unused
since the block was added in #14286 (every call site reads
`constants.X`). `const Socket = net.Socket` and the `#url` / `#isServer`
fields of `ServerHttp2Session` are never read either (`tsc
--noUnusedLocals`, re-checked by grep).
- `_nativeAssertSettings` (`$newRustFunction("h2_frame_parser.rs",
"jsAssertSettings")`) has been unused since #28074 gave http2.ts its own
`assertSettings()`. That made `js_assert_settings` in
`src/runtime/api/bun/h2_frame_parser.rs` (139 lines) and its facade
re-export in `src/runtime/api.rs` unreachable: the js2native codegen was
the only thing that named it. The three
`BUN_DECLARE_HOST_FUNCTION(BUN__HTTP2_*)` lines in `ZigGlobalObject.cpp`
are declarations of the Zig-era exports for the same helpers and have no
definition anywhere.
- `InspectorHTTPServerAgent::{startListening, stopListening,
getRequestBody, getResponseBody}` are TODO stubs that nothing can
dispatch to: the generated `HTTPServerBackendDispatcherHandler` in the
pinned WebKit only declares `enable()` / `disable()`, so these `virtual
... final` methods override nothing and have no callers.
- Declaration-only leftovers with no definition anywhere:
`Bun__DNSResolver__new` / `Bun__DNSResolver__cancel` (`BunObject.cpp`),
`jsBufferConstructorFunction_isBuffer` (`JSBuffer.cpp`,
`Buffer.isBuffer` is a JS builtin), `getStringOption` (`CryptoUtil.h`).
Plus the `IsIDLEnumeration` helper template (`IDLTypes.h`) and the
`globalBuiltinFunction` macro (`ZigGlobalObject.cpp`), each with zero
uses.
- uSockets: `us_internal_ssl_sni_userdata` and
`us_internal_ssl_handshake_abort` were added in #29932 and never called
(`us_socket_server_name_userdata`, which the first one wrapped, stays).
`us_cleanup_security_framework` (darwin) had no caller; the loader's
failure paths are the only thing that ever frees a `SecurityFramework`,
and they still do. The `SecTrustSettingsResult` typedef next to it was
unused too.
- Rust items no crate reaches (hawk `dead_public`, intersected over
linux-gnu, linux-musl, android, freebsd, darwin and windows-msvc, then
re-checked by hand): `ExprData::is_e_string`,
`ArrayHashMap::get_adapted`, the debug-only `Behavior::eq`, and
`js_parser::FunctionKind`, whose `Stmt` variant was never constructed.
`validate_function_name` only ever ran for function expressions, so the
parameter is gone and the one call site passes nothing; the error text
already said "function expression".
- Builtin-name tables: `Loader`, `byobRequest`, `controller`, `post`,
`resume`, `started`, `state`, `textDecoder` and `view` in
`BunBuiltinNames.h` have no `$name` / `@name` use in any builtin and no
`namePublicName()` / `namePrivateName()` use in C++ (each entry costs
two identifiers at VM startup). Their `builtins.d.ts` declarations go
with them, as do the six `$stream*` `--define`s in `replacements.ts` (no
builtin reads them; their only trace was the `.d.ts`), the `"Loader"`
entry of `globalsToPrefix` (the only bare `Loader` in src/js is inside a
block comment), and a duplicated `"Buffer"` entry.
- `scripts/find-dead-exports.ts` (303 lines, #31254) was a textual
approximation of the analysis `tools/hawk/` + `hawk.toml` now do
(#36184); nothing references it.

### Fix
- Deletes the items above; the only additions are the shorter
`validate_function_name` signature, one comment in `semver/lib.rs` that
named `get_adapted` (now names the surviving `get_index_adapted`), and
the re-export line in `api.rs`.
- Removing the `$newRustFunction` call is what makes the Rust function
removable: `generate-js2native.ts` emits the
`crate::api::bun::h2_frame_parser::js_assert_settings` thunk only for
calls it finds in src/js, so after this change nothing generated names
it either. `bundle-functions.ts` regenerates `BunBuiltinNames+extras.h`
from the names builtins actually use, so a builtin-name entry that were
still needed would be re-added by the build rather than break it; none
was.
- Verified: `bun bd` builds; `bun run rust:check-all` passes on all ten
target triples; `cargo fmt --check` and prettier are clean. `bun bd
test` passes on `test/js/node/http2/node-http2.test.js` (357),
`test/js/node/http2/node-http2-continuation.test.ts`,
`test/js/node/buffer.test.js`,
`test/js/node/crypto/node-crypto.test.js`,
`test/js/node/tls/node-tls-connect.test.ts`,
`test/js/web/streams/streams.test.js` and
`test/bundler/bundler_minify.test.ts`;
`test/js/node/tls/node-tls-server.test.ts` passes 69/70, the remaining
one (`SNICallback runs even when the requested servername matches the
bind hostname`) fails identically with the released binary in this
container (it binds `localhost` and connects to 127.0.0.1). The four
function-name diagnostics `validate_function_name` emits are unchanged
between the released binary and this build for both statement and
expression positions. `bun test test/internal/source-lints/` passes (158
tests); the new `dead-symbols-http2-settings-inspector-stubs.test.ts`
fails on main and passes here.
- Cross-checked against the 22 open dead-code PRs at the symbol level
(their diffs, not just file lists): nothing here is removed by any of
them. Two hunks are adjacent to open ones and will need a trivial rebase
on whichever side lands second: the `BUN__HTTP2_*` lines sit right under
the `Bun__NodeUtil__jsParseArgs` line #37788 removes, and the
`InspectorHTTPServerAgent` hunks are a few lines above the event
dispatchers #37454 removes. One item found dead here,
`JSValkeyClient::close_subscription_ctx`, is the renamed form of the
`SubscriptionCtx::close` that #38439 already removes, so it was left to
that PR.

### Background
- js2native: `$rust("file.rs", "name")` / `$newRustFunction(...)` calls
in src/js are collected at build time by
`src/codegen/generate-js2native.ts`, which emits one thunk per call into
`generated_js2native.rs` / `GeneratedJS2Native.h`. A Rust host function
is therefore reachable only while some builtin names it; the `api.rs`
facade module exists so the generated thunks have a stable path to call.
- `BunBuiltinNames.h` is the list of private identifiers (`@name` in
builtin JS, `builtinNames.namePrivateName()` in C++) that
`BunBuiltinNames` interns when a VM starts. `bundle-functions.ts` diffs
the names builtins use against this list and writes the difference to
`BunBuiltinNames+extras.h`, which is why removing an entry can only ever
remove startup work, never break a builtin.
- Inspector agents: the WebKit inspector protocol generator turns each
domain's JSON into a `*BackendDispatcherHandler` interface; a command
reaches an agent only through that interface. The HTTPServer domain bun
ships in its WebKit defines `enable` and `disable`, so methods an agent
declares beyond those are unreachable by construction.
- hawk (`tools/hawk/README.md`) is the workspace-wide reachability
analysis the repo uses for `pub` items, since rustc's `dead_code` treats
every `pub` item of a library crate as a root. Its per-target reports
were intersected so that anything live under some `cfg` on any shipped
platform was kept; the repr(C) FFI struct fields and flag/errno table
entries it also reports were left alone on purpose, as in #38703.

<details>
<summary>Found dead but left alone (follow-ups, not in this
diff)</summary>

- `bun_sys::ErrorCase::LeakFdOnFail` is never constructed (every
`make_lib_uv_owned_for_syscall` caller passes `CloseOnFail`), but
removing it means dropping the parameter at 13 call sites, several of
them in files open PRs are editing.
- `libusockets.h` still declares `us_udp_socket_receive`,
`us_udp_buffer_set_packet_payload`, `us_create_udp_packet_buffer` and
`us_udp_socket_bind` with no definitions, and `udp.c` carries a
commented-out `us_udp_packet_buffer_ecn`; both spots are adjacent to
hunks in #37454.
- `NapiEnv::currentFinalizer()` became unused in #37075 a week ago; left
for that work to settle, as #37454 did with its siblings.
- `replacements.ts` also emits a `$ImportKindLabelToId` define nothing
reads, but it comes out of the same loop as three live tables.
- `ws.js` `WebSocket.prototype.setSocket` (a throwing stub) and
`async_hooks` `AsyncResource.emitBefore/emitAfter` have no in-tree users
but are on exported classes.
- `scripts/packer/build-image.pkr.hcl` and `scripts/trace.sh` have no
invoker, but they are CI infrastructure rather than code; flagged for
whoever owns those.
- Everything else this pass turned up (about 270 C++ symbols and about
100 Rust items) is already deleted by one of the open dead-code PRs, and
the roughly 400 never-read Rust fields hawk reports are all repr(C)
mirrors of C structs.
</details>

---------

Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>

…uilt-in JS, bindgen, uSockets, and 66 Cargo manifests (#39732)

### Problem
- The tree carries code that nothing references: FFI shims with no
caller on either side, enum variants that are never constructed,
write-only fields, exports that no module imports, and Cargo dependency
edges that no source file uses.
- 16 dead-code PRs that removed much of this were closed as stale after
merge conflicts. Their deletions were never re-applied (list in the
notes).

### Fix
- Re-apply the deletions that still apply to current main and add new
ones in the same areas: `simdutf_sys`, `ncrypto` and the WebCore
bindings, `js_parser`, `bundler`, `js_printer`, `bun_install`, built-in
JS, bindgen, uSockets, and 66 Cargo manifests. 176 files, +95 / -3129
(`Cargo.lock` is -436 of that).
- Every deletion was checked again with `rg` over `src/`, `packages/`,
`src/codegen/` and the generated code. Items that became live again
since the old PRs stay (examples in the notes).
- No deletion duplicates an open dead-code PR. Deletions that need
#39618 or #39697 to land first are listed as follow-ups in the notes.
- Verified: `bun bd`, `bun run rust:check-all` (12 targets pass),
byte-identical bindgen output, `test/internal/source-lints`, and the
test files of the touched areas (list in the notes). New tests in
`transpiler.test.js` and `bundler_edgecase.test.ts` pin the two
diagnostics that `mark_strict_mode_feature` still emits and the class
body printing that `visit_class` still does.

### Background
- A Rust `extern "C"` declaration with no call site creates no link
reference, so a dead FFI chain is removed on both sides at once. Three
C++ definitions whose Rust side #39618 removes stay until that PR lands.
- `cargo check` covers the host target only. `rust:check-all` repeats it
for every shipped target, which proves the `#[cfg]`-gated deletions and
the Windows-only dependency removal (`bun_sys` -> `bun_output`).
- The dependency removals are manifest-only. `Cargo.lock` loses the
matching entries and nothing else: no version changes.

<details><summary>Notes</summary>

**Closed PRs re-applied**: #35437, #35559, #35775, #35880, #36115,
#36237, #37012, #37062, #37089, #37208, #37272, #37454, #37788, #38005,
#38439, #38703.

**Kept because they are live again on main**:
`GenericIndexOptional::{get, is_some, is_none}`, the WebSocket deflate
`OutOfMemory` variants, `V8Local::reinterpret`, `SystemErrno::MAX`,
`MarkPopErrorOnReturn::peekError`,
`ResourceTiming::populateServerTiming`, `UvHandle` in
`test/parallel/Channel.rs`, the `h2::FrameType` entries that `hawk.toml`
marks as a code table.

**Tests run**: node-http, node-http2, fetch headers, streams,
readable-stream-blob-consumed, filesink, transpiler, buffer, url,
FormData, TextEncoder, MessageChannel, serve-direct-readable-stream,
serve-body-leak, crypto key objects, crypto-rsa, scrypt, pbkdf2,
sqlite-sql, local-sql, postgres-simple-query-pipeline,
sql-helpers-validation, bun-outdated, websocket-server, test/internal
(bindgen, codegen outputs, source lints). The `localhost` proxy test in
node-http and the concurrent WebSocket send tests fail the same way on
unmodified main in this environment (the first is a `localhost`
resolution issue, the second is the 300k-message benchmark starving its
concurrent neighbours in a debug build).

**By kind**: C/C++ -1327, Rust -702 (+75, mostly signature updates at
call sites), built-in JS/TS -130, codegen TS -75 (+13), Cargo manifests
-459, `Cargo.lock` -436.

**simdutf_sys** (`simdutf.rs`, `bun-simdutf.cpp`,
`parsers/benches/support/simdutf_shim.cpp`): 16 shim chains with no
caller, each removed as Rust wrapper + `extern` declaration + C++
definition: `simdutf__convert_utf8_to_utf16le`, `_utf16be`,
`_utf16be_with_errors`, `convert_utf8_to_utf32_with_errors`,
`convert_valid_utf8_to_utf32`, `convert_utf16be_to_utf8_with_errors`,
`convert_valid_utf16be_to_utf8`, `convert_utf32_to_utf8_with_errors`,
`convert_valid_utf32_to_utf8`, `convert_utf32_to_utf16be_with_errors`,
`convert_valid_utf32_to_utf16be`,
`convert_utf16be_to_utf32_with_errors`,
`convert_valid_utf16be_to_utf32`, `utf8_length_from_utf16be`,
`utf32_length_from_utf16be`, `utf32_length_from_utf8`, plus the now
empty `utf32` modules and the `be` wrappers.

**ncrypto** (`ncrypto.h/.cpp`): `BignumPointer::isOne`,
`X509View::ifRsa`, `X509View::ifEc`, `BIOPointer::NewFp`,
`checkScryptParams`, `scrypt`, `pbkdf2`,
`EVPKeyCtxPointer::setRsaMgf1Md`, `Rsa::encrypt`, `Rsa::decrypt` and the
`RSA_Cipher` template, `Cipher::ForEach` with
`CipherCallbackContext`/`array_push_back`, `NCRYPTO_REQUIRE`,
`NCRYPTO_VERSION` and the version enum.

**JSC / WebCore bindings**: `ZigGlobalObject`:
`functionFulfillModuleSync` (and the `fulfillModuleSync` builtin name
plus `$fulfillModuleSync` stub), `JSDOMFileConstructor_getter/_setter`,
`navigatorObject`, `functionLazyNavigatorGetter`,
`GlobalObject_getPerformanceObject`, `hasNapiFinalizers`,
`jsFunctionNotImplemented`,
`jsFunctionCreateFunctionThatMasqueradesAsUndefined`,
`Zig__GlobalObject__getModuleRegistryMap`/`resetModuleRegistryMap`,
`NodeVM*ModulePrototype()` accessors, `ZIG_GLOBAL_OBJECT_DEFINED`.
`BunString.cpp`: `Bun__WTFStringImpl__ref`/`deref` definitions (Rust
inlines these; #39618 removes the declarations). `JSBuffer.cpp`: the
`JSValue`-name `validateOffset` overload and the three unused
`jsBufferConstructorAlloc*WithoutTypeChecks` JIT operations.
`NodeValidator`: `validateString(JSValue name)` and
`validateOneOf(span<ASCIILiteral>)`. `ScriptExecutionContext`:
`ensureOnMainThread`, `executionContext`. `napi.h`: `hasFinalizers`,
`currentFinalizer`, `isVMTerminating`. `IDLTypes.h`: `IDLDate`, the
`NullableTypeWithLessPadding` helpers and two includes.
`BunProcess.cpp`: three unused `*CodeGenerator` aliases.
`c-bindings.cpp`: `HNS_PER_SEC`, `NS_PER_HNS`, `HNS_PER_US`.
`BunCommonStrings.h`: `ConnectionWasClosed`, `ec`, `ed25519`, `rsa`,
`rsaPss`, `jwkDsa`, `jwkG`, `systemError`, `x25519`.
`BakeAdditionsToGlobalObject.h`: the never-read
`m_bakeGetAsyncLocalStorage` lazy property (the function is still
installed directly) and the `LazyPropertyOfGlobalObject` alias.
`JSBundlerPlugin.cpp`: the `JSBundlerPlugin__onVirtualModulePlugin`
declaration, which has no definition. WebCore:
`DeferredPromise::whenSettled` and the
`PromiseFunction`/`BindingPromiseFunction` adapters,
`JSEventListener::sourceURL/sourcePosition`, `Event::receivedTarget`,
`toJS(PerformanceObserverCallback)` and `callbackData()`,
`jsFetchHeaders_getRawKeys` (its only caller in `internal/http.ts` is
removed too), stale forward declarations in
`Performance.h`/`ResourceTiming.h`, and the commented-out
`BINDING_INTEGRITY` blocks in 8 generated-style files. `node/crypto`:
`JSPrivateKeyObjectConstructor` and `JSPublicKeyObjectConstructor` (4
files, superseded by `JSKeyObjectConstructor`). Bake:
`BakeRegisterProductionChunk`, `BakeProdSourceMap`, `BakeProduction.h`,
the `IncrementalGraph` log scope.

**uSockets**: `us_poll_ext`, `us_loop_iteration_number`,
`us_socket_is_tls`, `us_connecting_socket_get_loop`,
`us_udp_packet_buffer_local_ip` / `bsd_udp_packet_buffer_local_ip`.

**Rust**: `js_parser`: the six `StrictModeFeature` variants that are
never constructed (and the `can_be_transformed` branch),
`FnOnlyDataVisit::{class_name_ref,
should_replace_this_with_class_name_ref, is_inside_async_arrow_fn}` with
the `this` substitution path that was gated on the always-false flag
(the `shadow_ref` arena cell becomes a plain `Ref`). `bundler`:
`Linker::{resolver, hashed_filenames}`, `IS_CACHE_ENABLED`,
`InputFileFlags::IS_PLUGIN_FILE`, `parse_task::Step::ReadFile`.
`js_printer`: the write-only `Options::transform_only`. `bun_install`:
`CacheBehavior`/`ManifestLoad` (every caller passed
`LoadFromMemoryFallbackToDisk`, so the parameter and the memory-only
branch are gone from `by_name`, `by_name_hash` and
`by_name_hash_allow_expired`), `pub use patch_install as patch`.
`webcore`: `ReadableStream::detach_if_possible` (empty) and the `global`
parameter of `done()`, `BlobExt::{on_structured_clone_transfer,
get_mime_type}`, six `StartTag` variants that no sink uses. `server`:
`AnyRoute::ref_`, the write-only `OPENED_BIT`. `bun_core`: `concat`,
`ExternalShared::as_ptr`, `QuoteEscapeFormatFlags::ascii_only`.
`bun_io`: stale `Waker`/`Closer` re-exports. `bun_sys`: `UTIME_OMIT`.
`cli`: the never-read `IS_MAIN_THREAD` thread local. `css`:
`DeclarationContext::Keyframes`, the empty `generated_color_conversions`
module. `html_rewriter`: the `EndTag.replace` host function that
`html_rewriter.classes.ts` does not expose.

**Built-in JS/TS**: `internal/http.ts`: 29 unused symbol constants,
`filterEnvForProxies`, `getRawKeys`, `emitCloseNTAndComplete`,
`ClientRequestEmitState`. `node/http2.ts`: `kSettingNames`, three unused
primordials. `internal/sql/query.ts` and `internal/repl/node-shims.js`:
export entries nothing imports, and the `BuiltinModule` shim methods
nothing calls. `builtins.d.ts`: 8 stubs for builtin names that no longer
exist.

**bindgen** (`src/codegen/bindgen*.ts`): `allFunctions`,
`ArgStrategyChildItem`, `Variant.argStruct`,
`Struct.namespace`/`toString`, `FuncMetadata`/`exposedOn`/`ExposedOn`,
`FuncWithoutOverloads`, the dead `debug` binding, two shadowed duplicate
`case` labels and an unreachable `return`. Generated output is
byte-identical.

**Cargo**: 459 dependency lines across 66 manifests (mostly the
`strum`/`bstr`/`scopeguard`/`const_format`/`enum-map`/`enumset`/`libc`/`bitflags`
boilerplate block, plus 94 `bun_*` edges such as `bun_jsc ->
bun_simdutf_sys` and `bun_bundler_jsc -> 8 crates`). One dev-dependency
(`bun_router -> bun_js_parser`, checked with `cargo check -p bun_router
--tests`). The manifests that #39618 and #39697 already edit
(`collections`, `io`, `paths`, `css`, `shell_parser`, `sql`, `sql_jsc`)
were left alone.

**Rebase note**: main restructured the private builtin function
registration in `ZigGlobalObject::addBuiltinGlobals` into a table
(#39770). The conflict was resolved by dropping the
`k_fulfillModuleSync` row from the new table, which is the same
registration the first version of this PR removed. #39770 also touched
the two `JS*KeyObjectConstructor.h` files before this PR deletes them;
they are still unreferenced on main, so the deletion stands. Re-verified
after the rebase: `bun bd`, `rust:check-all` 12/12, and the test files
listed above.

**Follow-ups once open PRs land** (not done here to avoid duplicating
them): after #39618: the C++ definitions of `URL__fromJS`
(BunString.cpp) and `Bun__allocUint8ArrayForCopy` (ZigGlobalObject.cpp),
the seven `<Sink>()` constructor accessors in `ZigGlobalObject.h` that
only the generated `__getter` functions use, the Rust `extern`
declarations of `Bun__WTFStringImpl__ref/deref`, and
`BufferWriter::append_null_byte` (no writer ever sets it to true). After
#39697: the root `[workspace.dependencies] typed-arena` entry.
Independently of those: the `DeferredPromise::{promise, resolve(),
reject(...)}` overloads and `DOMPromise::whenPromiseIsSettled` have no
callers but sit next to code #39618 edits.
</details>

<!-- robobun:evidence:begin -->

---

**no test proof** · iteration 1 · Platform-specific test(s) that do not
run on this machine. Deferring to CI, which covers all platforms:
test/bundler/bundler_edgecase.test.ts

<!-- robobun:evidence:end -->