inspect.Signature: Make from_builtin to raise an exception if no signature can
be provided #20422
inspect.signature: Add support for decorated (wrapped) builtins #20425
inspect.Signature: ensure that non-default params don't follow default ones #20427
inspect.getfullargspec: Use inspect.signature API behind the scenes #17481
inspect.test.getfullargspec: Add a unittest to ensure correct annotations
handling #17481
inspect: Rename private helper function
inspect.Signature.bind: Update method signature to rule out possiblity
of name conflict between '__bind_self' and actual keyword argument to
'bind' or 'bind_partial'.
inspect.signature: Make sure that if a callable object has '_patialmethod'
attribute, that attribute is an instance of 'functools.partialmethod'.
inspect.Signature.from_function: Use CO_VARARGS & CO_VARKEYWORDS constants
asyncio: _fatal_error() of _UnixWritePipeTransport and _ProactorBasePipeTransport shouldn't log BrokenPipeError nor ConnectionResetError.

(Same behaviour as _SelectorTransport._fatal_error().)
asyncio: Refactoring: move write flow control to a subclass/mixin.
asyncio: Add write flow control to unix pipes.
asyncio: Get rid of _try_connected().
asyncio: Refactor drain logic in streams.py to be reusable.
asyncio: Pass through pause/resume from subprocess pipe proto to subprocess proto. Also kill dummy eof_received().
asyncio: wait_for() now accepts None as timeout (Victor Stinner).
asyncio: Fix _make_subprocess_transport(): pass extra value to the constructor.
asyncio: subprocess_shell() and subprocess_exec() now raise ValueError instead of assert.

Moreover, bufsize different than 0 is now considered as an error.
More asyncio news.
Issue #20373: generalize use of test.script_helper in test_warnings.  Patch by Arfrever.