Rollup merge of #145053 - lqd:known-bugs, r=jackh726

Add a lot of NLL `known-bug` tests

r? ``@jackh726``

As requested in rust-lang/rust#143093 (review) this extracts most tests from that PR and expands upon them as described.

The handful of linked-list cursor-like tests will also turn into polonius=next known-bugs in rust-lang/rust#143093 where the behavior w/r/t kills changes of course.

Author: Zalathar