Fix eraseFromParentWithdebugInsts to call a callback.
The recursivelyDeleteTriviallyDeadInstructions utility takes a
callBack to be called for every deleted instruction. However, it
wasn't passing this callBack to eraseFromParentWithdebugInsts. The
callback was used to update an iterator in some cases, so not calling
it resulted in iterator invalidation.
Doing this also cleans up the both APIs:
recursivelyDeleteTriviallyDeadInstructions and eraseFromParentWithdebugInsts.
