[MachineOutliner] Make KILLs invisible

At the point the outliner runs, KILLs don't impact anything, but they're still
considered unique instructions. This commit makes them invisible like
DebugValues so that they can still be outlined without impacting outlining
decisions.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327760 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed