#18466: merge with 3.3.

diff --cc Lib/collections/__init__.py
Simple merge

diff --cc Lib/test/datetimetester.py
Simple merge

diff --cc Lib/test/test_ast.py
Simple merge

diff --cc Lib/test/test_normalization.py
Simple merge

diff --cc Lib/test/test_urllib.py
Simple merge

diff --cc Misc/HISTORY
Simple merge

diff --cc Modules/_ssl.c
Simple merge

diff --cc Modules/_winapi.c
Simple merge

diff --cc PCbuild/readme.txt
Simple merge