b := v.Block
	config := b.Func.Config
	fe := b.Func.fe
	typ := &b.Func.Config.Types
	// match: (ConstString {str})
	// cond: config.PtrSize == 4 && str == ""
	// result: (StringMake (ConstNil) (Const32 <typ.Int> [0]))
	for {
		str := auxToString(v.Aux)
		if !(config.PtrSize == 4 && str == "") {
			break
		}
		v.reset(OpStringMake)