Renaming the constants for the .flags of PyMemberDef

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2019-03-18.14:42:30.742>
labels = ['interpreter-core', '3.8']
title = 'Renaming the constants for the .flags of PyMemberDef'
updated_at = <Date 2020-02-18.13:14:49.932>
user = 'https://github.com/matrixise'

bugs.python.org fields:

activity = <Date 2020-02-18.13:14:49.932>
actor = 'miss-islington'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2019-03-18.14:42:30.742>
creator = 'matrixise'
dependencies = []
files = []
hgrepos = []
issue_num = 36347
keywords = ['patch']
message_count = 18.0
messages = ['338232', '338261', '338280', '338366', '338400', '338453', '338720', '338731', '338732', '338745', '338758', '338759', '338760', '338764', '338789', '338794', '339440', '362207']
nosy_count = 6.0
nosy_names = ['ronaldoussoren', 'serhiy.storchaka', 'steve.dower', 'matrixise', 'josh.r', 'miss-islington']
pr_nums = ['12410', '12527', '12684']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue36347'
versions = ['Python 3.8']