Enable weak-intrinsics in compiler_builtins

This will allow the C++ intrinsics to replace them when they are linked
in explicitly.

[email protected]

Bug: 1445978
Change-Id: If37225fb6b6d49f6ccd2e548c2ca451bebdedbc1
Cq-Include-Trybots: luci.chromium.try:android-rust-arm32-rel,android-rust-arm64-dbg,android-rust-arm64-rel,linux-rust-x64-rel,linux-rust-x64-dbg,mac-rust-x64-dbg,win-rust-x64-dbg,win-rust-x64-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4567107
Commit-Queue: danakj <[email protected]>
Reviewed-by: Adrian Taylor <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1151214}
NOKEYCHECK=True
GitOrigin-RevId: 78de5406e5bfd08ffecf16f0db11156795426753

Author: danakj

rust/std/gnrt_config.toml

@@ -38,6 +38,7 @@ extra_gn_deps = [
 ]
 
 [crate.compiler_builtins]
+features = ['weak-intrinsics']
 # Dependencies of profiler_builtins must have instrumentation disabled
 remove_library_configs = ['//build/config/coverage:default_coverage']
 extra_gn_deps_to_ignore = ['//build/rust/std:profiler_builtins_group']

rust/std/rules/BUILD.gn

@@ -171,6 +171,7 @@ cargo_crate("compiler_builtins") {
     "compiler-builtins",
     "core",
     "rustc-dep-of-std",
+    "weak-intrinsics",
   ]
   build_root = "//third_party/rust-toolchain/lib/rustlib/src/rust/vendor/compiler_builtins-0.1.92/build.rs"
   build_sources = [ "//third_party/rust-toolchain/lib/rustlib/src/rust/vendor/compiler_builtins-0.1.92/build.rs" ]