Add some tests for associated-type-bounds issues
Closes#38917Closes#40093Closes#43475Closes#63591#47897 is likely closable too, but it needs an MCVE
~~#38917, #40093, #43475, #47897 all are mislabeled and shouldn't have the `F-associated-type-bounds` label~~
~~#71685 is also mislabeled as commented on in that thread~~