Using popcount should check the popcount feature flag not the SSE41 feature flag.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190258 91177308-0d34-0410-b5e6-96231b3b80d8
Add neverHasSideEffects=1 on a couple move instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190259 91177308-0d34-0410-b5e6-96231b3b80d8