Issue #16714: use 'raise' exceptions, don't 'throw'.

Patch by Serhiy Storchaka.

diff --cc Doc/library/os.rst
Simple merge

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

diff --cc Lib/pkgutil.py
Simple merge

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

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

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

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

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

diff --cc Modules/posixmodule.c
Simple merge