Clean up the heap types.

Author: ericsnowcurrently

Modules/_xxsubinterpretersmodule.c

@@ -145,6 +145,9 @@ get_module_state(PyObject *mod)
 static int
 traverse_module_state(module_state *state, visitproc visit, void *arg)
 {
+    /* heap types */
+    Py_VISIT(state->ChannelIDType);
+
     /* interpreter exceptions */
     Py_VISIT(state->RunFailedError);
 
@@ -160,6 +163,9 @@ traverse_module_state(module_state *state, visitproc visit, void *arg)
 static int
 clear_module_state(module_state *state)
 {
+    /* heap types */
+    Py_CLEAR(state->ChannelIDType);
+
     /* interpreter exceptions */
     Py_CLEAR(state->RunFailedError);