[X86] Mark the Key Locker instructions as NotMemoryFoldable to make the X86FoldTablesEmitter not crash.
loadiwkey and aesenc128kl share the same opcode but one is memory
and one is register. But they're behavior is quite different. We
were crashing because one has an output register and one doesn't
and the backend couldn't account for that. But since they aren't
foldable we can just add NotMemoryFoldable so they won't be looked at.