cannot alias the GEP. GEP pointer alias rule states this clearly:
A pointer value formed from a getelementptr instruction is associated with the
addresses associated with the first operand of the getelementptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84079 91177308-0d34-0410-b5e6-96231b3b80d8
