[libcxx-commits] [libcxx] [libc++] Remove explicit mentions of __need_FOO macros (PR #119025)

[Louis Dionne via libcxx-commits]

ldionne wrote:

Isn't that a circular dependency in the system headers?

After the patch, it looks like we have

```
system wchar.h ->... -> (include) system stdio.h -> ... -> system _G_config.h -> define __need_mbstate_t -> system wchar.h
```

How does including just the system's `wchar.h` header differ from that? Does that also fail (I can't imagine)?

https://github.com/llvm/llvm-project/pull/119025