Small boost to PySequence_Fast().  Lists build faster than tuples for
unsized iterable inputs.
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 024f97d..875c880 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1506,7 +1506,7 @@
 		return NULL;
 	}
 
-	v = PySequence_Tuple(it);
+	v = PySequence_List(it);
 	Py_DECREF(it);
 
 	return v;