Broken parent scope pointers in inlined DIVariables can cause
ensureAbstractVariableIsCreated to insert new abstract scopes, thus
invalidating the iterator in this loop and leading to hard-to-debug
crashes. Useful when manually reducing IR for testcases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219628 91177308-0d34-0410-b5e6-96231b3b80d8