// it, but give it an opcode number known only to us.
	instructions["MCR"] = aMCR

	return &Arch{
		LinkArch:       &arm.Linkarm,
		Instructions:   instructions,
		Register:       register,
		RegisterPrefix: registerPrefix,
		RegisterNumber: armRegisterNumber,
		IsJump:         jumpArm,
	}
}

func archArm64() *Arch {
	register := make(map[string]int16)
	// Create maps for easy lookup of instruction names etc.

func (p *Parser) atStartOfRegister(name string) bool {
	// Simple register: R10.
	_, present := p.arch.Register[name]
	if present {
		return true
	}
	// Parenthesized register: R(10).
	return p.arch.RegisterPrefix[name] && p.peek() == '('
}

// atRegisterShift reports whether we are at the start of an ARM shifted register.
// We have consumed the register or R prefix.
func (p *Parser) atRegisterShift() bool {