_Py_ReleaseInternedStrings(): Private API function to decref and
release the interned string dictionary.  This is useful for memory
use debugging because it eliminates a huge source of noise from the
reports.  Only defined when INTERN_STRINGS is defined.
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 9cf64ba..740cbe2 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -3217,3 +3217,13 @@
 	}
 #endif
 }
+
+#ifdef INTERN_STRINGS
+void _Py_ReleaseInternedStrings(void)
+{
+	if (interned) {
+		Py_DECREF(interned);
+		interned = NULL;
+	}
+}
+#endif /* INTERN_STRINGS */