[libcxx-commits] [libcxx] [libc++] stddef.h needs to #include_next for the new clang __need_ macros (PR #86252)

[Ian Anderson via libcxx-commits]

ian-twilightcoder wrote:

> > These macros are obscure. I would, in fact, much rather remove any knowledge of `__need_` macros from our headers.
> 
> I guess we could try removing the macros and the header guard and just always include_next. That feels like a riskier change for llvm 18 though.

Which is to say I'd rather do the safe thing right now and leave this PR the way it is, which is just to fixup the way this header already works rather than try to clean it up. At least for this release.

https://github.com/llvm/llvm-project/pull/86252