Auto merge of #102394 - dingxiangfei2009:issue-102317, r=oli-obk

Fix unwind drop glue for if-then scopes

cc `@est31`

Fix #102317
Fix #99852

This PR fixes the drop glue for unwinding from a panic originated in a drop while breaking out for the else block in an `if-then` scope.
MIR validation does not fail for the synchronous versions of the test program, because `StorageDead` statements are skipped over in the unwinding process. It is only becoming a problem when it is inside a generator where `StorageDead` must be kept around.