os.chdir(), os.getcwd() may crash on Windows in presence of races

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-02-22.01:00:15.765>
labels = ['extension-modules', '3.7', 'OS-windows', 'type-crash']
title = 'os.chdir(), os.getcwd() may crash on Windows in presence of races'
updated_at = <Date 2018-02-22.02:23:26.517>
user = 'https://github.com/izbyshev'

bugs.python.org fields:

activity = <Date 2018-02-22.02:23:26.517>
actor = 'izbyshev'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Extension Modules', 'Windows']
creation = <Date 2018-02-22.01:00:15.765>
creator = 'izbyshev'
dependencies = []
files = []
hgrepos = []
issue_num = 32904
keywords = ['patch']
message_count = 2.0
messages = ['312524', '312527']
nosy_count = 6.0
nosy_names = ['paul.moore', 'vstinner', 'tim.golden', 'zach.ware', 'steve.dower', 'izbyshev']
pr_nums = ['5802']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'crash'
url = 'https://bugs.python.org/issue32904'
versions = ['Python 2.7', 'Python 3.6', 'Python 3.7']