[libc-commits] [libc] [libc][wctype] Implement internal UTF8 wctype classification functions (PR #174607)

[Nikolas Klauser via libc-commits]

philnik777 wrote:

I'm pretty sure this is causing libc++ to fail building with errors like
```
/home/gha/actions-runner/_work/llvm-project/llvm-project/cmake/Modules/../../libc/src/__support/wctype_utils.h:19:5: error: 'LIBC_CONF_WCTYPE_MODE' is not defined, evaluates to 0 [-Werror,-Wundef]
     19 | #if LIBC_CONF_WCTYPE_MODE == LIBC_WCTYPE_MODE_UTF8
        |     ^
```
Please fix this ASAP - this is breaking our entire CI.

https://github.com/llvm/llvm-project/pull/174607