// Only simple ranges are accepted, like [Z0-Z3].
//
// The opening bracket has been consumed.
func (p *Parser) registerList(a *obj.Addr) {
	if p.arch.InFamily(sys.I386, sys.AMD64) {
		p.registerListX86(a)
	} else {
		p.registerListARM(a)
	}
}

func (p *Parser) registerListARM(a *obj.Addr) {
	// One range per loop.
	var maxReg int
	var bits uint16
	var arrangement int64