E0277: suggest dereferencing function arguments in more cases

[dianne]

This unifies and generalizes some of the logic in TypeErrCtxt::suggest_dereferences so that it will suggest dereferencing arguments to function/method calls in order to satisfy trait bounds in more cases.

Previously it would only fire on reference types, and it had two separate cases (one specifically to get through custom Deref impls when passing by-reference, and one specifically to catch #87437). I've based the new checks loosely on what's done for E0308 in FnCtxt::suggest_deref_or_ref: it will suggest dereferences to satisfy trait bounds whenever the referent is Copy, is boxed (& so can be moved out of the boxes), or is being passed by reference.

This doesn't make the suggestion fire in contexts other than function arguments or binary operators (which are in a separate case that this doesn't touch), and doesn't make it suggest a combination of &-removal and dereferences. Those would require a bit more restructuring, so I figured just doing this would be a decent first step.

Closes #90997

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