refactor(non_canonical_impls): lint starting from impls

[ada4a]

Based on #15520 (comment), with the following changes/additions:

• No longer use the Trait enum for quickly filtering out irrelevant impls -- instead, check the trait_of basically right away:
  1. pre-fetch DefIds of the relevant traits into the lint pass
  2. reuse cx.tcx.impl_trait_ref's output for the the DefId of the trait being implemented
  3. compare those DefIds, which should be very cheap
• Next, check whether self_ty implements the other relevant trait.
• Pre-filter impl items in the same (lazy) iterator, but delay the proc-macro check as much as possible

changelog: none

Not auto-assigning since @blyxyas and/or @Jarcho will be the ones reviewing it:
r? ghost

[ada4a]

Depends on #15520, so @rustbot label S-blocked

[github-actions]

Lintcheck changes for 2168603

Lint	Added	Removed	Changed
clippy::non_canonical_partial_ord_impl	0	1	0

This comment will be updated if you push new changes

[ada4a]

The PR was merged, so @rustbot label -S-blocked

[rustbot]

This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.