[libcxx-commits] [clang] [libcxx] [llvm] [Clang] Add warnings when mixing different charN_t types (PR #138708)

[Tom Honermann via libcxx-commits]

https://github.com/tahonermann requested changes to this pull request.

I like this, thanks for working on it! I added a number of mostly minor comments. I would like to see the warnings extended to `char` and `wchar_t` and doing that in a later change is fine. Some of my comments are intended to de-emphasize Unicode so that the warning category and diangostics remain applicable for non-Unicode encodings (even if we don't add diagnostics for such any time soon).

https://github.com/llvm/llvm-project/pull/138708