add CO_DOCSTRING flag by iritkatriel · Pull Request #30 · iritkatriel/cpython

>>> def f():
...    return "42"
... 
>>> def g():
...    """g"""
...    return "42"
... 
>>> f.__code__.co_consts
('42',)
>>> g.__code__.co_consts
('g', '42')
>>> f.__code__.co_flags
3
>>> g.__code__.co_flags
67