Function makeGenerators

tests/catch.hpp:3629–3631

    template<typename T, typename... Gs>
    auto makeGenerators( GeneratorWrapper<T>&& generator, Gs... moreGenerators ) -> Generators<T> {
        return Generators<T>(std::move(generator), std::forward<Gs>(moreGenerators)...);
    }
    template<typename T>
    auto makeGenerators( GeneratorWrapper<T>&& generator ) -> Generators<T> {
        return Generators<T>(std::move(generator));