Don't tamper with <undef> operands in MachineInstr::addRegisterKilled.

For an undef operand, MO.getReg() is meaningless and we should not use it.
Undef operands should be skipped entirely.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78095 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed