[clang] [clang-tools-extra] [clang] Extend diagnose_if to accept more detailed warning information (PR #70976)

[Erich Keane via cfe-commits]

https://github.com/erichkeane approved this pull request.

I think this is fine to commit, sorry my review took so long!

https://github.com/llvm/llvm-project/pull/70976