[incorrect_clone_impl_on_copy_type]: Do not lint if only has MaybeUninit fields

[Centri3]

Closes #11072
Closes #11071

changelog: Enhancement: [incorrect_clone_impl_on_copy_type]: Do not lint if only has MaybeUninit fields
changelog: Enhancement: [incorrect_clone_impl_on_copy_type]: Downgrade to complexity
changelog: Enhancement: [incorrect_clone_impl_on_copy_type]: Do not lint never-like enums

[rustbot]

r? @llogiq

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[llogiq]

I'm not sure about the lint group change, and there's one simplification I found. Otherwise this looks good to me.

Why complexity?

[Centri3]

Because it seemed there was mostly agreement of it in #11072, I put it in complexity because there isn't really any other category that has a more similar meaning to correctness whilst still being warn-by-default.

In most cases, this is a complexity issue; like Self(self.0). Sometimes, it's correctness. It's just the safest bet, really.

[bors]

☔ The latest upstream changes (presumably #11122) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #11095) made this pull request unmergeable. Please resolve the merge conflicts.

[llogiq]

I'm currently trying to catch up on my review queue. This looks good, pending a rebase.

@bors delegate+

[bors]

✌️ @Centri3, you can now approve this pull request!

If @llogiq told you to "r=me" after making some further change, please make that change, then do @bors r=@llogiq

[xFrednet]

Hey this is triage, I'm closing this due to inactivity. Currently, @Centri3 sadly doesn't have the time to continue this implementation. If anyone is interested in continuing this PR, you're more than welcome to create a new PR and push it over the finish line. :D

Thank you to @Centri3 and the reviewers for the time, that you already put into this!

@rustbot label +S-inactive-closed -S-waiting-on-author -S-waiting-on-review