* Try to match the module name pattern with module names constructed
starting from different parent directories of the filename.
E.g., for "/path/to/package/module" try to match with
"path.to.package.module", "to.package.module", "package.module" and
"module".
* Ignore trailing "/__init__.py".
* Ignore trailing ".pyw" on Windows.
* Keep matching with the full filename (without optional ".py" extension)
for compatibility.
* Only ignore the case of the ".py" extension on Windows.
Make `warnings.catch_warnings()` use a context variable for holding
the warning filtering state if the `sys.flags.context_aware_warnings`
flag is set to true. This makes using the context manager thread-safe in
multi-threaded programs.
Add the `sys.flags.thread_inherit_context` flag. If true, starting a new
thread with `threading.Thread` will use a copy of the context
from the caller of `Thread.start()`.
Both these flags are set to true by default for the free-threaded build
and false for the default build.
Move the Python implementation of warnings.py into _py_warnings.py.
Make _contextvars a builtin module.
Co-authored-by: Kumar Aditya <kumaraditya@python.org>
