5bcfd47f3f
regmove, regfill, and regspill have immediates which aren't value operands, so they aren't in the set of things that can be described by the existing constraint system. Consequently, constraints saying that the non-REX encodings only support registers that don't need REX prefixes don't work. Fow now, just remove the non-REX encodings, so that they don't get selected when they aren't valid. This fixes the last known issue with instruction shrinking, so it can be re-enabled.
This crate contains the core Cretonne code generator. It translates code from an intermediate representation into executable machine code.