Document missing type flags.

Author: ZeroIntensity

Doc/c-api/typeobj.rst

@@ -1498,6 +1498,45 @@ and :c:data:`PyType_Type` effectively act as defaults.)
          This flag is present in header files, but is not be used.
          It will be removed in a future version of CPython
 
+   .. c:macro:: Py_TPFLAGS_HAVE_VERSION_TAG
+         This is a :term:`soft deprecated` macro that does nothing.
+         Historically, this would indicate that the
+         :c:member:`~PyTypeObject.tp_version_tag` field was available and
+         initialized.
+
+   .. c:macro:: Py_TPFLAGS_INLINE_VALUES
+         This bit indicates that instances of this type will have an "inline values"
+         array (containing the object's attributes) placed directly after the end
+         of the object.
+
+         This requires that :c:macro:`Py_TPFLAGS_HAVE_GC` is set.
+
+         **Inheritance:**
+
+         This flag is not inherited.
+
+         .. versionadded:: 3.13
+
+   .. c:macro:: Py_TPFLAGS_IS_ABSTRACT
+      This bit indicates that this is an abstract type and therefore cannot
+      be instantiated.
+
+      **Inheritance:**
+
+      This flag is not inherited.
+
+      .. seealso::
+         :mod:`abc`
+
+   .. c:macro:: Py_TPFLAGS_HAVE_STACKLESS_EXTENSION
+
+         Internal. Do not set or unset this flag.
+         Historically, this was a reserved flag for use in Stackless Python.
+
+      .. warning::
+            This flag is present in header files, but is not be used.
+            This may be removed in a future version of CPython.
+
 
 .. c:member:: const char* PyTypeObject.tp_doc