* Suspend Python threads before fork()
Add stop-the-world thread suspension around fork() to prevent
deadlocks from locks held by dead parent threads in the child.
- Thread states: DETACHED / ATTACHED / SUSPENDED with atomic CAS
transitions matching _PyThreadState_{Attach,Detach,Suspend}
- stop_the_world / start_the_world: park all non-requester threads
before fork, resume after (parent) or reset (child)
- allow_threads (Py_BEGIN/END_ALLOW_THREADS): detach around blocking
syscalls (os.read/write, waitpid, Lock.acquire, time.sleep) so
stop_the_world can force-park via CAS
- Acquire/release import lock around fork lifecycle
- zero_reinit_after_fork: generic lock reset for parking_lot types
- gc_clear_raw: detach dict instead of clearing entries
- Lock-free double-check for descriptor cache reads (no read-side
seqlock); write-side seqlock retained for writer serialization
- fork() returns PyResult, checks PythonFinalizationError, calls
sys.audit
* Clear frame locals and stack on generator close
Add Frame::clear_locals_and_stack() to release references held by
closed generators/coroutines, matching _PyFrame_ClearLocals behavior.
Call it from Coro::close() after marking the coroutine as closed.
Update test_generators.py expectedFailure markers accordingly.
* Add dir_fd support for rmdir, remove/unlink, scandir
- rmdir: use unlinkat(fd, path, AT_REMOVEDIR) when dir_fd given
- remove/unlink: use unlinkat(fd, path, 0) when dir_fd given
- scandir: accept fd via fdopendir, add ScandirIteratorFd
- listdir: rewrite fd path to use raw readdir instead of nix::dir::Dir
- DirEntry: add d_type and dir_fd fields for fd-based scandir
- Update supports_fd/supports_dir_fd entries accordingly
* cells_free
* Use `ast.unparse` for decorator generation and every ut_method
* Ensure ut_method type for external patches
* use textwrap
* Apply patches to `test_os.py`
* Apoly on `test_xml_etree.py`
* Run on some test files
* Update `test_str.py`
* Update `test_logging.py` from 3.13.7
This test was marked as an expected failure. Because the garbage
collector is missing, that meant that the `os.scandir` object went
unclosed. This object was squatting on the file descriptors of all the
files contained in the test directory, which was breaking test_zipfile.
In cpython, they use `_PyTime_ROUND_FLOOR` to read time.
But in RustPython, we use `[Duration::from_secs_f64](https://doc.rust-lang.org/std/time/struct.Duration.html#method.try_from_secs_f64)` to read time.
Therefore, RustPython isn't affected by the rounding issue in the way
that cpython does. We can safely ignore the `0.5*1e-9` bit in
`ns_to_sec` function.
Initially this is only meant to be a small update for `test_io.py`.
But it turns out that `test.support` need a lot of cleanup especially
for `test.support.warnings_helper`.
