Convert redundant_clone to an analysis pass take 2

[Jarcho]

supersedes #11364
fixes #10940
fixes #10893
fixes #10870
fixes #10577
fixes #10545
fixes #10517

Don't worry about reviewing this as a whole, I'll be splitting it up into smaller chunks to be reviewed separately.

This comes with a separate dataflow framework than rustc's since many changes would be needed to track values correctly. As an example a mutable borrow of a pair of strings &mut (String, String) would need to cause both strings to hold different values and the only way to do that in rustc's framework is to track sub-statement positions. The new framework lets us easily do a preprocessing pass at the expense of not trivially supporting cursors.

Arena allocation is used heavily throughout. This simplifies some lifetimes both by using only a single lifetime parameter and not having to store as many owning values. It also avoids having a large number of small allocations that need to also be dropped.

No suggestions are give with the lint. This is unfortunate but they are non-trivial to add since removing the clone call is only correct in a subset of cases. Future uses of a projection may need to be changed; the clone call might be changed to a move of a different name (x.clone() -> y) or changed to a borrow. mem::take is needed in some cases as well.

The diagnostic output is currently a stand-in. I will be adding notes about where the values diverge and where the lifetimes of the pair of values end. Basically a message saying one value is modified, but the other isn't used after that point before it's dropped.

changelog: redundant_clone: Fix false positives where the clone result is stored in a local.
changelog: redundant_clone: Track the use of the clone throughout the function body rather than only checking for immediate consumption.
changelog: redundant_clone: Extended to analyze code in loops
changelog: redundant_clone: Track values inside fields rather than just tracking top level locals.

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