add a replacement API for PyCObject, PyCapsule #5630

All stdlib modules with C-APIs now use this.

Patch by Larry Hastings
diff --git a/Modules/datetimemodule.c b/Modules/datetimemodule.c
index 0c6e664..8ba3474 100644
--- a/Modules/datetimemodule.c
+++ b/Modules/datetimemodule.c
@@ -4792,11 +4792,10 @@
 	Py_INCREF(&PyDateTime_TZInfoType);
 	PyModule_AddObject(m, "tzinfo", (PyObject *) &PyDateTime_TZInfoType);
 
-        x = PyCObject_FromVoidPtrAndDesc(&CAPI, (void*) DATETIME_API_MAGIC,
-                NULL);
-        if (x == NULL)
-            return NULL;
-        PyModule_AddObject(m, "datetime_CAPI", x);
+    x = PyCapsule_New(&CAPI, PyDateTime_CAPSULE_NAME, NULL);
+    if (x == NULL)
+        return NULL;
+    PyModule_AddObject(m, "datetime_CAPI", x);
 
 	/* A 4-year cycle has an extra leap day over what we'd get from
 	 * pasting together 4 single years.