NLL fails to suggest using ref when a pattern is otherwise an impossible move

[pnkfelix]

In the case of ui/borrowck/borrowck-move-error-with-note.rs, the AST borrowck output (borrowck-move-error-with-note.stderr) includes suggestions like this:

LL |         Foo::Foo1(num1,
   |                   ---- hint: to prevent move, use `ref num1` or `ref mut num1`

but NLL (borrowck-move-error-with-note.nll.stderr) presents no such suggestion for errors it discovers in the MIR for match patterns.

Here are all the tests that I think involve this:

• ui/borrowck/borrowck-move-error-with-note.nll.stderr
• ui/borrowck/borrowck-vec-pattern-nesting.nll.stderr

[pnkfelix]

I suspect a good solution to this might tie into #51275, but I have not yet confirmed that. (The current form of that PR does not yet address any of the bugs above, but that might just be a matter of adding new cases to the match that PR is adding.)