Add an error check for a typo I accidentally made in a td file that caused an assert to fire.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188742 91177308-0d34-0410-b5e6-96231b3b80d8
Move AVX and non-AVX replication inside a couple multiclasses to avoid repeating each instruction for both individually.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188743 91177308-0d34-0410-b5e6-96231b3b80d8