Add more tests for r179925 to verify correct handling of signext/zeroext; strengthen condition check to require actual MVT::i32 virtual register types, just in case (no actual functionality change)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180138 91177308-0d34-0410-b5e6-96231b3b80d8