Overriding __new__ method with itself changes behaviour of the class

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2019-05-07.11:42:08.353>
labels = ['interpreter-core', '3.8', 'type-bug', '3.7']
title = 'Overriding __new__ method with itself changes behaviour of the class'
updated_at = <Date 2019-06-05.06:09:16.901>
user = 'https://bugs.python.org/alexey-muranov'

bugs.python.org fields:

activity = <Date 2019-06-05.06:09:16.901>
actor = 'orlnub123'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2019-05-07.11:42:08.353>
creator = 'alexey-muranov'
dependencies = []
files = []
hgrepos = []
issue_num = 36827
keywords = []
message_count = 9.0
messages = ['341705', '341709', '341710', '341711', '341728', '341783', '342185', '344661', '344675']
nosy_count = 5.0
nosy_names = ['rhettinger', 'SilentGhost', 'veky', 'orlnub123', 'alexey-muranov']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue36827'
versions = ['Python 3.7', 'Python 3.8']