Both functions raise an exception if `obj` does not support the relevant protocol.

METH_FASTCALL and METH_VECTORCALL flags

A new ``METH_VECTORCALL`` flag is added for specifying ``MethodDef`` structs. It is equivalent to the currently undocumented ``METH_FASTCALL | METH_KEYWORD`` flag.

The new flag specifies that the function has the type ``PyObject *(*call) (PyObject * self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwname)``