[CostModel][X86] Updated vXi8 and vXi16 Reverse/Alternate shuffle costs

Actual codegen is much better than the extract+insert patterns that was assumed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290962 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed