Issue #29012: Merge from 3.5

diff --cc Doc/reference/datamodel.rst
index aa03477fb85d735915b53a37da21a61327c97c63,cd28c147b279922423804a66f1618bb8a8b594e9..095a2380b379bc9f52697ca9a1b36d2cd1acd55b
--- 1/Doc/reference/datamodel.rst
--- 2/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@@ -788,12 -765,9 +788,11 @@@ Custom classe
     Special attributes: :attr:`~definition.__name__` is the class name; :attr:`__module__` is
     the module name in which the class was defined; :attr:`~object.__dict__` is the
     dictionary containing the class's namespace; :attr:`~class.__bases__` is a
-    tuple (possibly a singleton) containing the base classes, in the
-    order of their occurrence in the base class list; :attr:`__doc__` is the
-    class's documentation string, or ``None`` if undefined;
-    :attr:`__annotations__` (optional) is a dictionary containing
-    :term:`variable annotations <variable annotation>` collected during
+    tuple containing the base classes, in the order of their occurrence in the
 -   base class list; :attr:`__doc__` is the class's documentation string, or
 -   ``None`` if undefined.
++   base class list; :attr:`__doc__` is the class's documentation string,
++   or ``None`` if undefined; :attr:`__annotations__` (optional) is a dictionary
++   containing :term:`variable annotations <variable annotation>` collected during
 +   class body execution.
  
  Class instances
     .. index::