Do not assert when trying to add a meta data operand with
MachineInstr::addOperand().



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192707 91177308-0d34-0410-b5e6-96231b3b80d8
Guard the debug temp variable with NDEBUG to avoid warning/error with NDEBUG defined.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192709 91177308-0d34-0410-b5e6-96231b3b80d8