[clang] WIP Add suppress weak loop assumptions visitor (PR #111258)

[Balazs Benics via cfe-commits]

steakhal wrote:

Ideally, I should use a location context and expr pairs a map keys, to make sure these numbers are kept separate for different stack frames. I leave it for the reader this time, to not complicate things further. Once we settle, I'll do that too.

https://github.com/llvm/llvm-project/pull/111258