This wasn't doing anything useful. They weren't explicitly used
anywhere, and the RegScavenger ignores reserved registers.
This for some reason caused a random scheduling change in the test.
Getting the check lines to pass is too frustrating, and there's probably
not too much value in checking the vector case's operands N times.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250794 91177308-0d34-0410-b5e6-96231b3b80d8
08e1ec066d