Author: Daniel Richard G. <skunk@iSKUNK.ORG>
Description: Don't use thumbv7neon Rust target

In the armhf build, Chromium wants to use a Rust target for NEON that
Debian does not ship. Force it to use the target that we do have.

  [883/52770] ACTION //build/rust/std:find_stdlib(//build/toolchain/linux/unbundle:default_for_rust_host_build_tools)
  FAILED: default_for_rust_host_build_tools/obj/build/rust/std/libstd.rlib [...]
  python3 ../../build/rust/std/find_std_rlibs.py --rust-bin-dir ../../../../../usr/bin --output default_for_rust_host_build_tools/obj/build/rust/std --depfile default_for_rust_host_build_tools/obj/build/rust/std/stdlib.d --depfile-target std --rustc-revision rustc\ 1.85.0\ \(4d91de4e4\ 2025-02-17\)\ \(built\ from\ a\ source\ tarball\) --target thumbv7neon-unknown-linux-gnueabihf
  Traceback (most recent call last):
    File "/build/reproducible-path/chromium-136.0.7103.59/out/Release/../../build/rust/std/find_std_rlibs.py", line 132, in <module>
      sys.exit(main())
               ~~~~^^
    File "/build/reproducible-path/chromium-136.0.7103.59/out/Release/../../build/rust/std/find_std_rlibs.py", line 87, in main
      name for name in os.listdir(rustlib_dir) if name.endswith('.rlib')
                       ~~~~~~~~~~^^^^^^^^^^^^^
  FileNotFoundError: [Errno 2] No such file or directory: '/usr/lib/rustlib/thumbv7neon-unknown-linux-gnueabihf/lib'

--- a/build/config/rust.gni
+++ b/build/config/rust.gni
@@ -200,7 +200,7 @@ if (is_linux || is_chromeos) {
       # The thumbv7 vs. armv7 distinction is for legacy reasons and both
       # targets in fact target Thumb, see:
       # https://github.com/rust-lang/rust/issues/44722
-      if (arm_use_neon) {
+      if (false && arm_use_neon) {
         rust_abi_target = "thumbv7neon-unknown-linux-gnueabi" + float_suffix
       } else {
         rust_abi_target = "armv7-unknown-linux-gnueabi" + float_suffix