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

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

I think there are multiple bugs here, at least one seems to be preexisting. It seems that perhaps diagnostics issued early enough in the driver do not seem to honor diagnostic groups: https://godbolt.org/z/sh4e9noe1

Note how it's missing `[-Woption-ignored]` like you get in: https://godbolt.org/z/xvn59hEva

However, note how we're missing that diagnostic *entirely* now: https://godbolt.org/z/znr63dj6o

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