This is a 1-line patch (with a TODO for AVX because that will affect even more regression tests).
I've stared at the Intel docs for the various movq versions, but it's not clear to me exactly what the difference is between the 0xD6 (MOVPQI2QImr) and 0x7E (MOVSDto64mr) opcodes.
Please can you add a domain fix to keep this on the integer domain - search for 'add forces execution domain'