[clang] [llvm] [C++23] [CLANG] Adding C++23 constexpr math functions: fmin, fmax and frexp. (PR #88978)

[Hubert Tong via cfe-commits]

https://github.com/hubert-reinterpretcast commented:

Partial review comments.

https://github.com/llvm/llvm-project/pull/88978