ImplicitNullChecks: Clear kill/dead flags when moving instructions around

The values are marked as livein in the successor blocks so marking them
as killed or dead was wrong.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304366 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed