Generate Rust bindings that match Bazel-built V8 archives (#57644)

## Why

Pre-generated bindings can disagree with native V8 layouts, including CppGC member storage and the inline typed-array size. Source archives need bindings generated with the same headers, defines, and target configuration.

## What changed

- Generate bindings through Bazel using the archive's C++ compilation metadata, and include them in Darwin and Linux release pairs and source builds.
- Select native Windows MSVC archives and matching bindings together with `--//:rusty_v8_from_source=true`, and generate target-specific Windows GNU bindings.
- Pin a corrected `rusty_v8` revision for Cargo and Bazel, and track native Windows LLVM tools and resources as action inputs so pin changes invalidate cached actions.
- Run release and canary Cargo smoke tests with explicit target triples, required Linux linkers, and `--include-ignored`.

## Testing

Add `codex-v8-poc` coverage for CppGC member size, alignment, tracing, and weak references; typed-array contents and backing-store promotion; and microtask queues across garbage collection and context reassignment. Enable the otherwise ignored CppGC ABI checks for Bazel source builds and staged release smoke tests.

GitOrigin-RevId: 9edfa057a0ef2e323543bb8132c070d336ded1b2

patches/rusty_v8_prebuilt_out_dir.patch

@@ -1,6 +1,6 @@
-# What: make `rusty_v8` accept Bazel-provided archives and bindings for the
-# windows-gnullvm experiment.
-# Scope: `rusty_v8` build.rs only; no V8 source or Bazel rule changes.
+# Make rusty_v8 use the Bazel-provided archive and bindings. Mark the Git
+# checkout's vendored third_party directory as a package so rules_rs does not
+# stage libc++ test names containing '=' as Cargo build-script runfiles.
 
 --- a/build.rs
 +++ b/build.rs
@@ -72,3 +72,7 @@
        if target.contains("msvc") {
          // nothing to link to
        } else if target.contains("apple")
+--- /dev/null
++++ b/third_party/BUILD.bazel
+@@ -0,0 +1 @@
++package(default_visibility = ["//visibility:private"])