asm and port the mmx vector shuffle test to it.
Not thrilled with how it handles the stack manipulation logic, but I'm
much less bothered by that than I am by updating the test manually. =]
If anyone wants to teach the test checks management script about stack
adjustment patterns, that'd be cool too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229268 91177308-0d34-0410-b5e6-96231b3b80d8
