[libcxx-commits] [libcxx] [libc++] Introduce unversioned namespace macros (PR #133009)

[Louis Dionne via libcxx-commits]

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

LGTM with minor comments. I think it's especially nice to make our intent explicit when we use an unversionned namespace.

https://github.com/llvm/llvm-project/pull/133009