[libcxx-commits] [libcxx] [libc++] Handle _LIBCPP_HAS_NO_{THREADS, LOCALIZATION} consistently with other carve-outs (PR #98319)

[Louis Dionne via libcxx-commits]

ldionne wrote:

> I can see this change affecting some users. For example, those who use CMake's `try_compile` and include `<thread>` to test whether threading is available. For that reason I feel we should add this change to the release notes.

I'm really not too concerned about that -- I think these are relatively niche features so the likelihood of someone relying on `try_compile` to detect something like this seems rather small. You bring up an excellent point, I just have the feeling that most people probably won't notice.

> I also wonder whether it would be better to land this after LLVM-19 has branched. Just in case it causes real world breakage.

I would like to unblock some of the modularization rework before the release branch. Given that I think the risk for breakage is fairly small compared to many of the things we do, I'd rather not wait.

https://github.com/llvm/llvm-project/pull/98319