Remove an old workaround for a compiler that EOL'd years ago.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191643 91177308-0d34-0410-b5e6-96231b3b80d8
ObjectSizeOffsetEvaluator: Don't run into infinite recursion if we have a cyclic GEP.

Those can occur in dead code. PR17402.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191644 91177308-0d34-0410-b5e6-96231b3b80d8