* @param s scope in which the name has to be unique
     * @return fresh synthetic name
     */
    private Name makeSyntheticName(Name name, Scope s) {
        do {
            name = name.append(
                    target.syntheticNameChar(),
                    names.empty);
        } while (lookupSynthetic(name, s) != null);
        return name;
    }