[clang-tools-extra] [clang-tidy] add modernize-use-constexpr check (PR #146553)

[Julian Schmidt via cfe-commits]

5chmidti wrote:

I'll have very little access to my machine this month, but I'll move this forward in October (maybe with a bit before that) and also split the PR into smaller ones.

https://github.com/llvm/llvm-project/pull/146553