Guarantee that divmod() and PyNumber_Divmod() return a 2-tuple

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-09-14.10:13:50.305>
labels = ['interpreter-core', 'type-feature', '3.8']
title = 'Guarantee that divmod() and PyNumber_Divmod() return a 2-tuple'
updated_at = <Date 2018-09-17.19:55:24.197>
user = 'https://github.com/serhiy-storchaka'

bugs.python.org fields:

activity = <Date 2018-09-17.19:55:24.197>
actor = 'serhiy.storchaka'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2018-09-14.10:13:50.305>
creator = 'serhiy.storchaka'
dependencies = ['34716']
files = []
hgrepos = []
issue_num = 34676
keywords = ['patch']
message_count = 6.0
messages = ['325341', '325361', '325364', '325398', '325423', '325543']
nosy_count = 6.0
nosy_names = ['rhettinger', 'mark.dickinson', 'zach.ware', 'serhiy.storchaka', 'p-ganssle', 'xtreak']
pr_nums = ['9301']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue34676'
versions = ['Python 3.8']