[SystemZ]  Bugfix for MVCLoop CC clobbering.

MVCLoop clobbers CC (since it emits a compare/branch), but this was not
modelled.

Review: Ulrich Weigand

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331627 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed