Check return result from Py_InitModule*().  This API can fail.

Probably should be backported.
diff --git a/Modules/symtablemodule.c b/Modules/symtablemodule.c
index 7a52aae..c90d765 100644
--- a/Modules/symtablemodule.c
+++ b/Modules/symtablemodule.c
@@ -53,6 +53,8 @@
 	PyObject *m;
 
 	m = Py_InitModule("_symtable", symtable_methods);
+	if (m == NULL)
+		return;
 	PyModule_AddIntConstant(m, "USE", USE);
 	PyModule_AddIntConstant(m, "DEF_GLOBAL", DEF_GLOBAL);
 	PyModule_AddIntConstant(m, "DEF_LOCAL", DEF_LOCAL);