[clang] [llvm] [analyzer][NFC] Reorganize Z3 report refutation (PR #95128)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

> Please have a second look at the llvm-related changes. Z3 has a really dangerous C API. I shot myself in the foot literally 3 times while working on this PR.

> And btw notice that I removed the proof=false configuration as that is the default AFAIK, so that's why that is missing.

OK, I'll re-check the footgun handling either today or tomorrow.

https://github.com/llvm/llvm-project/pull/95128