Auto merge of #44984 - Maaarcocr:master, r=nikomatsakis

Create NormalizeTy query

As part of the effort to solve #44891,  I've created the normalize_ty query.

As outlined in the issue this meant:

- renamed `normalize_associated_type()` to `normalize_associated_type_in()`
- created the `normalize_ty` query
- substituted the use of memoize with the query

This PR is not ready. While running tests, one of the incremental ones failed. [This](https://pastebin.com/vGhH6bv6) is the error I got.