MipsAsmParser: Try to unbreak tests to add extra check.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172315 91177308-0d34-0410-b5e6-96231b3b80d8
GlobalOpt: Avoid jump on uninitialized value.

Found by valgrind.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172318 91177308-0d34-0410-b5e6-96231b3b80d8
MipsDisassembler.cpp: Prune DecodeHWRegs64RegisterClass() to suppress a warning. [-Wunused-function]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172319 91177308-0d34-0410-b5e6-96231b3b80d8