overlapped.c: Fix usage of the union

* read_buffer can only be used for TYPE_READ and TYPE_ACCEPT types
* write_buffer can only be used for TYPE_WRITE type
asyncio: Future.set_exception(exc) should instantiate exc if it is a class.
asyncio: Fix granularity of test_utils.TestLoop.
asyncio: Fix misc whitespace issues.
Issue #20452: add more info in case of test_asyncio failure to try to debug the
failure on buildbot "x86 Ubuntu Shared 3.x"
Issue #20452: Oops, fix debug code :-/

Add also event more debug info
Issue #20452: select and selectors round (again) timeout away from zero for
poll and epoll

Improve also debug info to analyze the issue
asyncio: Fix error message in BaseEventLoop.subprocess_shell(). Patch written
by Vajrasky Kok.
Issue #20452: Remove debug code, no more needed
Issue #20311, #20452: poll and epoll now round the timeout away from zero,
instead of rounding towards zero, in select and selectors modules:
select.epoll.poll(), selectors.PollSelector.poll() and
selectors.EpollSelector.poll(). For example, a timeout of one microsecond
(1e-6) is now rounded to one millisecondi (1e-3), instead of being rounded to
zero.

Mention the change in Misc/NEWS.
asyncio: Fix _UnixWritePipeTransport, raise BrokenPipeError when the pipe is
closed, but only if there was pending write
Issue #20455: asyncio: write a new write pipe transport class for proactor (on
Windows) instead of using the "duplex" pipe transport. The new class uses a
simpler overlapped read to be notified when the pipe is closed. So the protocol
doesn't need to implement eof_received(): connection_lost() is called instead.
_UnixWritePipeTransport has the same approach.
Issue #20390: Removing detritus from Argument Clinic "file preset" name change.
Windows buildbot: use --timeout feature in Tools/buildbot/test.bat

Use the same default timeout than Makefile: 1 hour (3600 seconds).
Issue #20455: math.ceil() returns an int in Python 3, no need to cast the
result again to int
Issue #20455: asyncio: use the same code to round a timeout than the selectors
module

Sort also imports
Issue #20455: Add a resolution attribute to IocpProactor (1 ms)
Issue #20452: test_asyncio: Add more info if the test fails
The function name for cmath.isinf in PyArg_ParseTuple() was wrong.
Typo fix