[libc-commits] [libc] [libc] Use clang's scoped atomics if available from the compiler (PR #74769)

[Jon Chesterfield via libc-commits]

JonChesterfield wrote:

RPC side is right. The enum class and int casting looks messy to me, and it's weird that these aren't template parameters, but you're following the existing model so I expect that's fine.

We should have some fences that can be lowered to device scope around port opening, separate to this patch.

https://github.com/llvm/llvm-project/pull/74769