Excepting MOVPRFX, which isn't a reduction. Presumably it is
placed within the group because of its encoding.
Backports commit 047cec971d2791b206677b954227ea92ff7ee3db from qemu
These were the instructions that were stubbed out when
introducing the decode skeleton.
Backports commit 39eea56172e668cc4cca611ed9166779df54ac63 from qemu
Including only 4, as-yet unimplemented, instruction patterns
so that the whole thing compiles.
Backports commit 38388f7ee3adc04a7e7246c04352451c4f8d00fb from qemu