[SystemZ] Also clear kill flag for index reg in splitMove().

Discovered by running fp-move-05.ll with -verify-machineinstrs (added
to test case run).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251298 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed