cpython/Misc/NEWS.d/next/Core and Builtins/2017-10-30-12-44-50.bpo-31902.a07fa57.rst

Fix the ``col_offset`` attribute for ast nodes ``ast.AsyncFor``,
``ast.AsyncFunctionDef``, and ``ast.AsyncWith``. Previously, ``col_offset``
pointed to the keyword after ``async``.