Auto merge of #124227 - compiler-errors:hack-check-method-res, r=estebank

Make sure that the method resolution matches in `note_source_of_type_mismatch_constraint`

`note_source_of_type_mismatch_constraint` is a pile of hacks that I implemented to cover up another pile of hacks.

It does a bunch of re-confirming methods, but it wasn't previously checking that the methods it was looking (back) up were equal to the methods we previously had. This PR adds those checks.

Fixes #118185

Author: bors