Fix build on gcc: PySetIter_Type should be static in definition
part also.
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 34e64e4..7d23284 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -602,7 +602,7 @@
 	return NULL;
 }
 
-PyTypeObject PySetIter_Type = {
+static PyTypeObject PySetIter_Type = {
 	PyObject_HEAD_INIT(&PyType_Type)
 	0,					/* ob_size */
 	"setiterator",				/* tp_name */