PathEntryFinder instances which only define find_module().

Reported by Yukihiro Nakadaira.

On Windows, the codec of sys.stdout is implemented in Python. At exit, the
codec may be unloaded before the destructor tries to write something to
sys.stdout.

This silences a Coverity complain.

Remove unused variables.

cleaning other modules.  The sys and builtins modules are cleaned last.

I'll look into re-enabling them in issue #20128.

This addresses issue #20199, if I got it right.  The deprecation and
replacement lists are based on the importlib documentation.

for bound methods.  Previous to this change, it displayed "self" for methods
implemented in Python but not methods implemented in C; it is now both
internally consistent and consistent with inspect.Signature.

when compiled with VS 2010 or above.  Initial patch by Tabrez Mohammed.

scope_id: (host, port).

test_sock_connect_address()

The "exc" variable was not defined, pass a BrokenPipeError exception instead.

Use self._loop instead of self._transport._loop, because transport._loop is set
to None at process exit.

env var), document the default debug mode

Add also a PYTHONASYNCIODEBUG environment variable to debug coroutines since
Python startup, to be able to debug coroutines defined directly in the asyncio
module.

Initial patch by Nick Coghlan.

On Mac OS X Tiger (and older), getsockname() returns a zero-length address for
UNIX socket, and so 'sockname' extra info is None.

of BaseEventLoop