mmap constructor resets the file pointer on Windows

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2022-02-25.20:47:49.811>
labels = ['type-bug', '3.9', 'expert-IO', '3.11', 'library', '3.10', 'OS-windows']
title = 'mmap constructor resets the file pointer on Windows'
updated_at = <Date 2022-02-26.05:08:48.141>
user = 'https://bugs.python.org/benrg'

bugs.python.org fields:

activity = <Date 2022-02-26.05:08:48.141>
actor = 'eryksun'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)', 'Windows', 'IO']
creation = <Date 2022-02-25.20:47:49.811>
creator = 'benrg'
dependencies = []
files = []
hgrepos = []
issue_num = 46858
keywords = []
message_count = 2.0
messages = ['414039', '414071']
nosy_count = 6.0
nosy_names = ['paul.moore', 'tim.golden', 'benrg', 'zach.ware', 'eryksun', 'steve.dower']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue46858'
versions = ['Python 3.9', 'Python 3.10', 'Python 3.11']