Method operator new

tests/test_class.cpp:316–319

    struct HasOpNewDel {
        std::uint64_t i;
        static void *operator new(size_t s) {
            py::print("A new", s);
            return ::operator new(s);
        }
        static void *operator new(size_t s, void *ptr) {
            py::print("A placement-new", s);
            return ptr;