Fixes [`trait_duplication_in_bounds`] false positives

[aldhsu]

Fixes #9076 #9151 #8757. Partially fixes #8771.

changelog: [trait_duplication_in_bounds]: Reduce number of false positives.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Manishearth (or someone else) soon.

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[flip1995]

Assigning this to me, since I reviewed the last PR. I pormise that it won't take me 2 months this time!

r? @flip1995

[flip1995]

Thanks! This was the only thing for now. The comments added are great! I now have to go through the tests, but I don't expect that there's anything left for you to do :+1:

[aldhsu]

@flip1995 I worked on a refactor to lint in one pass https://github.com/rust-lang/rust-clippy/pull/9167/commits/8bae517c2d540dcf62bff12ba7404a23a4233d99. I thought it would be harder than it turned out to be. I've added it to this PR. I'm happy to split it to a separate PR if you prefer.

[flip1995]

Maybe in another PR :D

@bors r+

[bors]

:pushpin: Commit 8bae517c2d540dcf62bff12ba7404a23a4233d99 has been approved by flip1995

It is now in the queue for this repository.

[bors]

:hourglass: Testing commit 8bae517c2d540dcf62bff12ba7404a23a4233d99 with merge 84df61c06eb36602022e758878afe66479ba0769...

[bors]

:sunny: Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test Approved by: flip1995 Pushing 84df61c06eb36602022e758878afe66479ba0769 to master...