init_exceptions(): Decref `doc' so it doesn't leak.
diff --git a/Python/exceptions.c b/Python/exceptions.c
index 4596c27..2726519 100644
--- a/Python/exceptions.c
+++ b/Python/exceptions.c
@@ -909,6 +909,7 @@
     PyObject* args;
 
     PyDict_SetItemString(mydict, "__doc__", doc);
+    Py_DECREF(doc);
     if (PyErr_Occurred())
 	Py_FatalError("exceptions bootstrapping error.");