[libcxx-commits] [libcxx] [libc++] Implement C++20 atomic_ref (PR #76647)

[Louis Dionne via libcxx-commits]

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

This basically LGTM once CI is all passing. Please don't hesitate to ping me on Discord if you need help with specific CI failures and how they should map to `UNSUPPORTED` and/or `XFAIL`. This is tricky to get right and atomic is full of them.

Thanks for the patch, there was a lot of work needed to get it into its current state but I think this is really good!

https://github.com/llvm/llvm-project/pull/76647