This is a proof of concept to add constant pool decoding to more instructions.
So far I've only added support for add/sub/and/or/xor. I've printed the and/or/xor as bytes, since it was easier to think about small immediates. Maybe we should print them in hex?
I only regenerated a few tests just as as a demonstration.
Can you detect a splat here and print something like "[0x1234 splat]"? That would greatly improve readability in the common case IMO, and make it clear in the odd case when the constant is not a splat.