create multiprocessing.SharedMemory by pointing to existing memoryview

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-02-26.23:46:31.295>
labels = ['3.8', 'library', 'performance']
title = 'create multiprocessing.SharedMemory by pointing to existing memoryview'
updated_at = <Date 2021-06-22.14:43:45.738>
user = 'https://bugs.python.org/DariuszTrawinski'

bugs.python.org fields:

activity = <Date 2021-06-22.14:43:45.738>
actor = 'petr.viktorin'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2020-02-26.23:46:31.295>
creator = 'Dariusz Trawinski'
dependencies = []
files = []
hgrepos = []
issue_num = 39767
keywords = []
message_count = 1.0
messages = ['362754']
nosy_count = 1.0
nosy_names = ['Dariusz Trawinski']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'performance'
url = 'https://bugs.python.org/issue39767'
versions = ['Python 3.8']