refactor queries that don't accept inference variables to use canonicalization

[nikomatsakis]

In #86866 we found various queries that were ICEing when used with inference variables. #86866 worked around these ICEs via simple checks or imprecision, but these queries likely out to be rewritten to use canonicalization or other less hacky techniques.

Discussion with @arora-aman in this Zulip topic, starting about here.

[nikomatsakis]

In the code, some of the places that have to change are marked with FIXME(#86868).

[b-naber]

I could work on this, or do you want to take this, @arora-aman ?

[jackh726]

@b-naber I think you should feel free to claim and work on this

[ouz-a]

If mentorship is still available I would like to work on this

[vincenzopalazzo]

@rustbot claim