fix windows tests (#16662)

From Robert Collins.

--HG--
extra : amend_source : ae25368dd52821d6e0c810ac84fc3ae8dc3bade8
clear BufferedRWPair weakrefs on deallocation (closes #22517)

--HG--
branch : 3.3
extra : source : 9b4673d7b046fc8b169a5e7f962493999444d3f3
merge 3.3 (#22517)

--HG--
branch : 3.4
merge 3.4 (#22517)
prevent overflow in unicode_repr (closes #22520)

--HG--
branch : 3.3
merge 3.3 (#22520)

--HG--
branch : 3.4
merge 3.4 (#22520)
Fix "warning: comparison between signed and unsigned integer expressions"
-Wsign-compare warnings in unicodeobject.c.  These were all a result
of sizeof() being unsigned and being compared to a Py_ssize_t.
Not actual problems.
Issue #22396: On 32-bit AIX platform, don't expose os.posix_fadvise() nor
os.posix_fallocate() because their prototypes in system headers are wrong.

--HG--
branch : 3.4
extra : amend_source : e5d2ce1782130973ccb3d3cab29d5149f4b21cf8
(Merge 3.4) Issue #22396: On 32-bit AIX platform, don't expose
os.posix_fadvise() nor os.posix_fallocate() because their prototypes in system
headers are wrong.
faulthandler: suppress crash reporter directly in test functions written to
crash.

--HG--
extra : amend_source : 7862740c8fdd0c1115903548213487ac08f5d107
faulthandler: _sigsegv() and _sigabrt() don't accept parameters

--HG--
branch : 3.4
faulthandler: test_gil_released() now uses _sigsegv() instead of _read_null(),
because _read_null() cannot be used on AIX. On AIX, reading from NULL is
allowed: the first page of memory is a mapped read-only on AIX.

--HG--
branch : 3.4
(Merge 3.4) faulthandler: test_gil_released() now uses _sigsegv() instead of
_read_null(), because _read_null() cannot be used on AIX. On AIX, reading from
NULL is allowed: the first page of memory is a mapped read-only on AIX.

_read_null() and _sigabrt() don't accept parameters.
Remove pointless "vile hack" that can cause the build step to fail when some extension modules can't be imported.

See issue #5309 for the build failures, issue #458343 for the original motivation.
remove merge goop from f86fde20e9ce
Issue #22448: asyncio, cleanup _run_once(), only iterate once to remove delayed
calls that were cancelled.

--HG--
branch : 3.4
(Merge 3.4) Issue #22448: asyncio, cleanup _run_once(), only iterate once to
remove delayed calls that were cancelled.
Issue #18711: Add a new `PyErr_FormatV` function, similar to `PyErr_Format` but accepting a `va_list` argument.
Reorganize C API docs of the exception API