Issue #19219: Speed up marshal.loads(), and make pyc files slightly (5% to 10%) smaller.
diff --git a/Include/marshal.h b/Include/marshal.h
index 0c69655..77d9c5e 100644
--- a/Include/marshal.h
+++ b/Include/marshal.h
@@ -7,7 +7,7 @@
 extern "C" {
 #endif
 
-#define Py_MARSHAL_VERSION 3
+#define Py_MARSHAL_VERSION 4
 
 PyAPI_FUNC(void) PyMarshal_WriteLongToFile(long, FILE *, int);
 PyAPI_FUNC(void) PyMarshal_WriteObjectToFile(PyObject *, FILE *, int);