Verifier: Check that all instructions have their parent pointers set up correctly. This helps with catching problems caused by IRBuilder abuse such as the one fixed in CFE r222487.
Verifier: Check that all instructions have their parent pointers set up
correctly. This helps with catching problems caused by IRBuilder abuse
such as the one fixed in CFE r222487.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@222488 91177308-0d34-0410-b5e6-96231b3b80d8

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