[X86][SSE] Add MOVHPSrm to domain tables

[RKSimon]

Summary

This is also a shorter encoding on SSE.

What should I do for the avx512 cases? Do you want me to add a fadd stage to force domain?

[craig.topper]

lib/Target/X86/X86InstrInfo.cpp

9446

Does moving from MOVHPS to UNPCKLPD cause us to potentially access unaligned memory? MOVHPS doesn't have an alignment requirement, but UNPCKLPD does.

[gadi.haber]

lib/Target/X86/X86InstrInfo.cpp

9446

Yes. 64-bit memory operand has no restrictions while 128-bit (unpcklpd) always does in SSE except for movu* instructions.

[RKSimon]

I'm going to abandon this and instead investigate adding custom domain switching (PR34873) - I'm concerned that MOVPS only references 64-bits on a load but PUNPCKLPD/PUNPCKLQDQ reference 128-bits.