pep-0492: Add "async/await in CPython code base" section.

pep-0492.txt

@@ -815,7 +815,7 @@ This proposal preserves 100% backwards compatibility.
 
 
 asyncio
--------
+'''''''
 
 ``asyncio`` module was adapted and tested to work with coroutines and
 new statements.  Backwards compatibility is 100% preserved, i.e. all
@@ -832,8 +832,8 @@ The required changes are mainly:
    Deprecate ``async()`` function.
 
 
-Migration strategy
-''''''''''''''''''
+asyncio migration strategy
+''''''''''''''''''''''''''
 
 Because *plain generators* cannot ``yield from`` *native coroutine
 objects* (see `Differences from generators`_ section for more details),
@@ -842,6 +842,23 @@ decorated with ``@asyncio.coroutine`` *before* starting to use the new
 syntax.
 
 
+async/await in CPython code base
+''''''''''''''''''''''''''''''''
+
+There is no use of ``await`` names in CPython.
+
+``async`` is mostly used by asyncio.  We are addressing this by
+renaming ``async()`` function to ``ensure_task()`` (see `asyncio`_
+section for details.)
+
+Another use of ``async`` keyword is in ``Lib/xml/dom/xmlbuilder.py``,
+class ``DocumentLS``.  ``async`` property is not documented, not
+tested, and is not used anywhere.  Methods that were likely supposed to
+work with it -- ``_set_async()`` and ``_get_async()`` -- are not used
+anywhere either.  These methods will be deprecated in 3.5 and removed
+in 3.6.
+
+
 Grammar Updates
 ---------------