Sækja Python 3.8 3.8.4

Security
- bpo-41162: Audit hooks are now cleared later during finalization to avoid missing events.
- bpo-29778: Ensure python3.dll is loaded from correct locations when Python is embedded (CVE-2020-15523).
Core and Builtins
- bpo-41247: Always cache the running loop holder when running asyncio.set_running_loop.
- bpo-41252: Fix incorrect refcounting in _ssl.c’s _servername_callback().
- bpo-41218: Python 3.8.3 had a regression where compiling with ast.PyCF_ALLOW_TOP_LEVEL_AWAIT would aggressively mark list comprehension with CO_COROUTINE. Now only list comprehension making use of async/await will tagged as so.
- bpo-41175: Guard against a NULL pointer dereference within bytearrayobject triggered by the bytearray() + bytearray() operation.
- bpo-39960: The “hackcheck” that prevents sneaking around a type’s __setattr__() by calling the superclass method was rewritten to allow C implemented heap types.
Library
- bpo-41235: Fix the error handling in ssl.SSLContext.load_dh_params().
- bpo-41193: The write_history() atexit function of the readline completer now ignores any OSError to ignore error if the filesystem is read-only, instead of only ignoring FileNotFoundError and PermissionError.
- bpo-41043: Fixed the use of glob() in the stdlib: literal part of the path is now always correctly escaped.
- bpo-39384: Fixed email.contentmanager to allow set_content() to set a null string.
IDLE
- bpo-37765: Add keywords to module name completion list. Rewrite Completions section of IDLE doc.
- bpo-41152: The encoding of stdin, stdout and stderr in IDLE is now always UTF-8.