[Opt] Fix use after free (erase) in mem2reg #628
Merged
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Description
The pass collects operations to clean up in one container and use two loops to erase different kinds. The problem is that the first loop was erasing operations while leaving their pointers. Then, the second loop would try to cast the erased operations of those pointers and the garbage.
This PR simply changes the behavior to first drop all uses of the operations and, on a third loop, actually to the erasing.