Remove bad command line arguments from the Mac Linker with Rust

When linker plugin LTO is enabled on Apple, rustc passes invalid
command line arguments to the linker. They are valid elsewhere but
not known by the Apple linker.

Fortunately, on Apple we have a python script that is used to invoke
the linker. So we drop them from the command line in linker_driver.py
for now.

Upstream issue: rust-lang/rust#60059

R=hans@chromium.org

Bug: 1446796
Change-Id: Idc051457cff194616ac9b0063e3fd255fdd261cc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4659997
Reviewed-by: Adrian Taylor <adetaylor@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Reviewed-by: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1164710}

build/toolchain/apple/linker_driver.py

@@ -125,7 +125,13 @@ def run(self):
                 assert driver_action[0] not in linker_driver_actions
                 linker_driver_actions[driver_action[0]] = driver_action[1]
             else:
-                compiler_driver_args.append(arg)
+                # TODO(crbug.com/1446796): On Apple, the linker command line
+                # produced by rustc for LTO includes these arguments, but the
+                # Apple linker doesn't accept them.
+                # Upstream bug: https://github.com/rust-lang/rust/issues/60059
+                BAD_RUSTC_ARGS = ['-plugin-opt=O3', '-plugin-opt=mcpu=core2']
+                if arg not in BAD_RUSTC_ARGS:
+                    compiler_driver_args.append(arg)
 
         if self._object_path_lto is not None:
             compiler_driver_args.append('-Wl,-object_path_lto,{}'.format(