[libcxx] [llvm] [libc++] Format the code base (PR #74334)

[Petr Hosek via llvm-commits]

petrhosek wrote:

It looks like the formatting changed the order of includes in `libcxx/src/support/win32/thread_win32.cpp`:
```diff
- #include <windows.h>
- #include <process.h>
#include <fibersapi.h>
+ #include <process.h>
+ #include <windows.h>
```
I didn't have a chance to verify this locally yet, but I suspect this is the culprit.

https://github.com/llvm/llvm-project/pull/74334