Add X86 instruction selection for VPERM2I128 when AVX2 is enabled. Merge VPERMILPS/VPERMILPD detection since they are pretty similar.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145238 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed