[x86] Regenerate an avx512 test with my script to provide a nice
baseline for updates from the new vector shuffle lowering.

I've inspected the results here, and I couldn't find any register
allocation decisions where there should be any realistic way to register
allocate things differently. The closest was the imul test case. If you
see something here you'd like register number variables on, just shout
and I'll add them.