[libcxx-commits] [libcxx] [libcxxabi] [libc++][RFC] Always define internal feature test macros (PR #89178)

[Louis Dionne via libcxx-commits]

ldionne wrote:

> 
> Oh, I was only looking at build configurations, I completely forgot about that. I see quite a bit more when I expand the scope for things like that, e.g. https://github.com/abseil/abseil-cpp/blob/192e959b16809f751d565b53a949b21129d904fb/absl/hash/internal/hash.h#L73

This specific usage looks wrong. I think it was a workaround for the fact that feature-test macros didn't take into account availability on the deployment target, but this has been fixed now. Checking for the feature-test macro only should be sufficient.

https://github.com/llvm/llvm-project/pull/89178