[libcxx-commits] [libcxx] [libc++] Prevent cycle from including __mbstate_t.h within wchar.h (PR #200940)

[Sean Perry via libcxx-commits]

perry-ca wrote:

These are the only uses of `__mbstate_t.h`.  So delete the file and clean up module map etc too?  We should do the same to cxx03 as it has the same code.

https://github.com/llvm/llvm-project/pull/200940