Method operator new

tests/test_class.cpp:331–334

    struct HasOpNewDelSize {
        std::uint32_t i;
        static void *operator new(size_t s) {
            py::print("B new", s);
            return ::operator new(s);
        }
        static void *operator new(size_t s, void *ptr) {
            py::print("B placement-new", s);
            return ptr;