[compiler-rt] [compiler-rt] Use __atomic builtins whenever possible (PR #84439)

[via llvm-commits]

Enna1 wrote:

https://github.com/llvm/llvm-project/blob/main/compiler-rt/lib/sanitizer_common/CMakeLists.txt#L125 should also be updated?

https://github.com/llvm/llvm-project/pull/84439