bpo-39999: Improve compatibility of the ast module. (GH-19056)

* Re-add removed classes Suite, slice, Param, AugLoad and AugStore.
* Add docstrings for dummy classes.
* Add docstrings for attribute aliases.
* Set __module__ to "ast" instead of "_ast".

1 files changed, 8 insertions, 6 deletions

diff --git a/Doc/whatsnew/3.9.rst b/Doc/whatsnew/3.9.rst
index 9f9e895..b11c29b 100644
--- a/Doc/whatsnew/3.9.rst
+++ b/Doc/whatsnew/3.9.rst
@@ -593,12 +593,19 @@ Deprecated
 
   (Contributed by Victor Stinner in :issue:`39353`.)
 
-* :mod:`ast` classes ``Index`` and ``ExtSlice`` are considered deprecated
+* :mod:`ast` classes ``slice``, ``Index`` and ``ExtSlice`` are considered deprecated
   and will be removed in future Python versions.  ``value`` itself should be
   used instead of ``Index(value)``.  ``Tuple(slices, Load())`` should be
   used instead of ``ExtSlice(slices)``.
   (Contributed by Serhiy Storchaka in :issue:`32892`.)
 
+* :mod:`ast` classes ``Suite``, ``Param``, ``AugLoad`` and ``AugStore``
+  are considered deprecated and will be removed in future Python versions.
+  They were not generated by the parser and not accepted by the code
+  generator in Python 3.
+  (Contributed by Batuhan Taskaya in :issue:`39639` and :issue:`39969`
+  and Serhiy Storchaka in :issue:`39988`.)
+
 * The :c:func:`PyEval_InitThreads` and :c:func:`PyEval_ThreadsInitialized`
   functions are now deprecated and will be removed in Python 3.11. Calling
   :c:func:`PyEval_InitThreads` now does nothing. The :term:`GIL` is initialized
@@ -704,11 +711,6 @@ Removed
   defining ``COUNT_ALLOCS`` macro.
   (Contributed by Victor Stinner in :issue:`39489`.)
 
-* The ``ast.Suite``, ``ast.Param``, ``ast.AugLoad`` and ``ast.AugStore``
-  node classes have been removed due to no longer being needed.
-  (Contributed by Batuhan Taskaya in :issue:`39639` and :issue:`39969`
-  and Serhiy Storchaka in :issue:`39988`.)
-
 
 Porting to Python 3.9
 =====================