[libcxx-commits] [libcxx] [libc++] Improve performance of std::atomic_flag on Windows (PR #163524)

[via libcxx-commits]

https://github.com/huixie90 approved this pull request.

Since this change is not an ABI break and we can make incremental improvement. I am fine with the change.

https://github.com/llvm/llvm-project/pull/163524