// match: (MOVBZreg (RISBGZ x {r}))
	// cond: r.OutMerge(0x000000ff) != nil
	// result: (RISBGZ x {*r.OutMerge(0x000000ff)})
	for {
		if v_0.Op != OpS390XRISBGZ {
			break
		}
		r := auxToS390xRotateParams(v_0.Aux)
		x := v_0.Args[0]
		if !(r.OutMerge(0x000000ff) != nil) {
			break
		}
		v.reset(OpS390XRISBGZ)
		v.Aux = s390xRotateParamsToAux(*r.OutMerge(0x000000ff))
		v.AddArg(x)
		return true