Auto merge of #42724 - Mark-Simulacrum:tests, r=alexcrichton
Add tests for a few issues.
Fixes #41998
Fixes #38381
Fixes #37515
Fixes #37510
Fixes #37366
Fixes #37323
Fixes #37051
Fixes #36839
Fixes #35570
Fixes #34373
Fixes #34222
Certainly not all of the E-needstest issues right now, but I started to get bored.