signalmodule.c does "is" comparisons for SIG_IGN and SIG_DFL

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-09-10.19:49:19.914>
labels = ['type-bug', 'library']
title = 'signalmodule.c does "is" comparisons for SIG_IGN and SIG_DFL'
updated_at = <Date 2018-08-23.23:54:00.666>
user = 'https://github.com/mdickinson'

bugs.python.org fields:

activity = <Date 2018-08-23.23:54:00.666>
actor = 'berker.peksag'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2016-09-10.19:49:19.914>
creator = 'mark.dickinson'
dependencies = []
files = []
hgrepos = []
issue_num = 28069
keywords = []
message_count = 3.0
messages = ['275687', '275688', '275696']
nosy_count = 3.0
nosy_names = ['mark.dickinson', 'berker.peksag', 'serhiy.storchaka']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue28069'
versions = ['Python 2.7', 'Python 3.5', 'Python 3.6']