bpo-40170: Always define PyIter_Check() as a function (GH-24548)
diff --git a/Include/abstract.h b/Include/abstract.h
index 0bd1ca9..a47c944 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -324,7 +324,7 @@ PyAPI_FUNC(PyObject *) PyObject_Format(PyObject *obj,
returns itself. */
PyAPI_FUNC(PyObject *) PyObject_GetIter(PyObject *);
-/* Returns 1 if the object 'obj' provides iterator protocols, and 0 otherwise.
+/* Returns non-zero if the object 'obj' provides iterator protocols, and 0 otherwise.
This function always succeeds. */
PyAPI_FUNC(int) PyIter_Check(PyObject *);