Auto merge of #87998 - nneonneo:master, r=oli-obk

Auto merge of #87998 - nneonneo:master, r=oli-obk

Avoid spurious "previous iteration of loop" errors

Only follow backwards edges during `get_moved_indexes` if the move path is definitely initialized at loop entry. Otherwise, the error occurred prior to the loop, so we ignore the backwards edges to avoid generating misleading "value moved here, in previous iteration of loop" errors.

This patch also slightly improves the analysis of inits, including `NonPanicPathOnly` initializations (which are ignored by `drop_flag_effects::for_location_inits`). This is required for the definite initialization analysis, but may also help find certain skipped reinits in rare cases.

Patch passes all non-ignored src/test/ui testcases.

Fixes #72649.