[AArch64] Extend the number of scalar instructions supported in the AdvSIMD
scalar integer instruction pass.

This is a patch I had lying around from a few months ago.  The pass is
currently disabled by default, so nothing to interesting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214779 91177308-0d34-0410-b5e6-96231b3b80d8