Auto merge of rust-lang#134465 - lcnr:type-verifier, r=<try>

cleanup `TypeVerifier`

We should merge it with the `TypeChecker` as we no longer bail in cases where it encounters an error since rust-lang#111863.

It's quite inconsistent whether a check lives in the verifier or the `TypeChecker`, so this feels like a quite impactful cleanup. I expect that for this we may want to change the `TypeChecker` to also be a MIR visitor 🤔 this is non-trivial so I didn't fully do it in this PR.

Best reviewed commit by commit.

r? `@compiler-errors` feel free to reassign however

Author: bors