The pause instruction is architecturally defined to be the `REP NOP`
instruction.
This allows people to use this instruction as a backwards compatible
pause without checking for CPUID support. In fact there is no way to
check if the hardware implements this as a `REP NOP` or a `PAUSE`.
If you have new enough hardware then this just ends up being a PAUSE.
Pass this PAUSE over to our host to help out applications that are
writing spin loops with a PAUSE in it, which we were deleting
previously.
Ryan Houdek
c633661121