Replace PyObject_CallFunction() with fastcall

Replace
    PyObject_CallFunction(func, "O", arg)
and
    PyObject_CallFunction(func, "O", arg, NULL)
with
    _PyObject_CallArg1(func, arg)

Replace
    PyObject_CallFunction(func, NULL)
with
    _PyObject_CallNoArg(func)

_PyObject_CallNoArg() and _PyObject_CallArg1() are simpler and don't allocate
memory on the C stack.

Modules/_collectionsmodule.c

@@ -538,7 +538,7 @@ deque_copy(PyObject *deque)
         return NULL;
     }
     if (old_deque->maxlen < 0)
-        return PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "O", deque, NULL);
+        return _PyObject_CallArg1((PyObject *)(Py_TYPE(deque)), deque);
     else
         return PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "Oi",
             deque, old_deque->maxlen, NULL);