[libcxx-commits] [libcxx] [libc++] Drop support for the C++20 Synchronization Library before C++20 (PR #82008)

[Louis Dionne via libcxx-commits]

ldionne wrote:

This patch isn't completely finished, but I wanted to get some feedback and see what people think.

@huixie90 @jiixyj This would greatly help with the refactoring around `atomic_wait` & friends.

CC @llvm/libcxx-vendors 

https://github.com/llvm/llvm-project/pull/82008