[libcxx-commits] [libcxx] [libc++] Define the __cpp_lib_atomic_ref feature test macro (PR #98081)

[Arthur Eubanks via libcxx-commits]

aeubanks wrote:

this has caused static asserts in some code expecting `std::atomic_ref<float>::is_always_lock_free` to be true. I believe #93427 would fix it

https://github.com/llvm/llvm-project/pull/98081