Rollup merge of #120126 - sjwang05:issue-102269, r=compiler-errors

Suggest `.swap()` when encountering conflicting borrows from `mem::swap` on a slice

This PR modifies the existing suggestion by matching on `[ProjectionElem::Deref, ProjectionElem::Index(_)]` instead of just `[ProjectionElem::Index(_)]`, which caused us to miss many cases. Additionally, it adds a more specific, machine-applicable suggestion in the case we determine `mem::swap` was used to swap elements in a slice.

Closes #102269

Author: matthiaskrgr