There was a switch fall-through in the parser for textual LLVM that caused

There was a switch fall-through in the parser for textual LLVM that caused
bogus comparison operands to default to eq/oeq. Fix that, fix a couple of
tests that accidentally passed and test for bogus comparison opeartors
explicitly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171733 91177308-0d34-0410-b5e6-96231b3b80d8