ARM paired GPR COPY was being lowered to two MOVr without CC. This
patch puts the CC back.
My test is a reduction of the case where I encountered the issue,
64-bit atomics use paired GPRs.
The issue only occurs with selectionDAG, FastISel doesn't encounter it
so I didn't bother calling it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186226 91177308-0d34-0410-b5e6-96231b3b80d8
