* Implement Windows SemLock in _multiprocessing module
Add SemLock class using Windows semaphore APIs (CreateSemaphoreW,
WaitForSingleObjectEx, ReleaseSemaphore) so test_multiprocessing
suites are no longer skipped with "lacks a functioning sem_open".
Also add sem_unlink as no-op and flags dict for Windows.
* Fix _multiprocessing recv to return bytes and improve SemLock reliability
- recv() now returns bytes instead of int (matching CPython)
- Remove spurious GetLastError() check after CreateSemaphoreW
- Add signal checking during blocking SemLock acquire
* Include winerror in OSError.__reduce__ on Windows
* Remove expectedFailure for tests now passing with Windows SemLock
* Fix OSError.__reduce__ to preserve winerror when filename is None
When filename is None, __reduce__ was reconstructing a 2-element
(errno, msg) tuple, dropping the winerror at position 3 in the
original args. Use the original args tuple instead, matching CPython.
* Validate maxvalue > 0 in SemLock and document winerror __reduce__ divergence
* Reject embedded null characters in mmap tagname and _winapi file mapping names
* Downgraded skips in tests
* Fixed failing tests
* Fixed test_ftplib + test_socket + test_ssl + test_threaded_import failures
* Removed comments about which tests are run in which environment
* Addressed PR comments
* Annotated skips on failing tests
* Removed unneeded tests
* Removed unneeded sys import from test_ftplib
* Added annotation to test_ftplib
* Readded skipIf to test_cleanup_with_symlink_modes with a more general ENV_POLLUTING_TESTS_WINDOWS
* Addressed PR comments
* Made changes to minimize diff in PR
* Apply suggestion from @youknowone
---------
Co-authored-by: Jeong, YunWon <69878+youknowone@users.noreply.github.com>
There are a substantial number of socket tests that are disabled due to
`bind(): bad family` errors. It seems like RustPython only supports a
small subset of the required connection families, so the failing tests
are broken for the same reasons.
