[libcxx-commits] [libcxx] [libc++] Granularize the <new> header (PR #119270)

[Louis Dionne via libcxx-commits]

ldionne wrote:

> What's your goal with this patch?

This disentangles the code which previously had a mix of many #ifdefs, a non-versioned namespace and a versioned namespace. It also makes it clearer which parts of are implemented on Windows by including <new.h>.

My original goal was to fix some modules issues I was seeing with `__libcpp_allocate`, but after doing the split that doesn't seem to help. I do think it helps readability though, so I've uploaded the patch.

https://github.com/llvm/llvm-project/pull/119270