zipfile: inconsistent doc for ZIP64 file size

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-12-19.09:04:33.319>
labels = ['3.8', 'type-bug', '3.7', 'docs']
title = 'zipfile: inconsistent doc for ZIP64 file size'
updated_at = <Date 2018-09-21.09:22:26.652>
user = 'https://github.com/mndavidoff'

bugs.python.org fields:

activity = <Date 2018-09-21.09:22:26.652>
actor = 'mndavidoff'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2016-12-19.09:04:33.319>
creator = 'mndavidoff'
dependencies = []
files = []
hgrepos = []
issue_num = 29013
keywords = []
message_count = 10.0
messages = ['283597', '284448', '284449', '284469', '284475', '284519', '325728', '325963', '325974', '325980']
nosy_count = 5.0
nosy_names = ['docs@python', 'python-dev', 'berker.peksag', 'serhiy.storchaka', 'mndavidoff']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'needs patch'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue29013'
versions = ['Python 3.6', 'Python 3.7', 'Python 3.8']