Just in case there is ever an issue with _posixsubprocess's use of
vfork() due to the complexity of using it properly and potential
directions that Linux platforms where it defaults to on could take, this
adds a failsafe so that users can disable its use entirely by setting
a global flag.

No known reason to disable it exists. But it'd be a shame to encounter
one and not be able to use CPython without patching and rebuilding it.

See the linked issue for some discussion on reasoning.

Also documents the existing way to disable posix_spawn.

Move the following API from Include/opcode.h (public C API) to a new
Include/internal/pycore_opcode.h header file (internal C API):

* EXTRA_CASES
* _PyOpcode_Caches
* _PyOpcode_Deopt
* _PyOpcode_Jump
* _PyOpcode_OpName
* _PyOpcode_RelativeJump

Fix signal.NSIG value on FreeBSD to accept signal numbers greater
than 32, like signal.SIGRTMIN and signal.SIGRTMAX.

* Add Py_NSIG constant.
* Add pycore_signal.h internal header file.
* _Py_Sigset_Converter() now includes the range of valid signals in
  the error message.

In the limited C API version 3.11 and newer, the following functions
no longer cast their object pointer argument with _PyObject_CAST() or
_PyObject_CAST_CONST():

* Py_REFCNT(), Py_TYPE(), Py_SIZE()
* Py_SET_REFCNT(), Py_SET_TYPE(), Py_SET_SIZE()
* Py_IS_TYPE()
* Py_INCREF(), Py_DECREF()
* Py_XINCREF(), Py_XDECREF()
* Py_NewRef(), Py_XNewRef()
* PyObject_TypeCheck()
* PyType_Check()
* PyType_CheckExact()

Split Py_DECREF() implementation in 3 versions to make the code more
readable.

Update the xxlimited.c extension, which uses the limited C API
version 3.11, to pass PyObject* to these functions.

Fixes gh-91880.

It always failed on non-UTF-8 locale and prevented running regrtests.

Closes #90633

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

* Add a new :gh:`...` role for GitHub issues.

* Fix a GitHub id to use the :gh: role.

* Add Misc/NEWS entry.

* Refactoring and rephrasing.

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>

Similar to the rewrite of email/mime/image.py and associated test after the
deprecation of imghdr.py, thisrewrites email/mime/audio.py and associated
tests after the deprecation of sndhdr.py.

Closes #91885

The test relies on precision being set to 9, but some ways of
invoking this test leave it set to 28 instead. I don't know
exactly how it happens, but setting the precision directly should
make the behavior consistent.

Other aspects of typing aren't covered yet; I'll do that in a
separate PR.

The context manager result has the "filename" attribute.

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>

1. It makes them interned.
2. It allows to add comments to individual opcodes.

… information (GH-91531)

Also inline necessary functionality from `sndhdr` into `email.mime.audio` for `MIMEAudio`.

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>

…xecutable for Windows (GH-31279)

This bring the API to be on a par with Unix-like systems.

…ing in re (GH-91660)

Also test that all extra cases are in BMP.

…H-91702)

In expression (?(group)...) an appropriate re.error is now
raised if the group number refers to not defined group.

Previously it raised RuntimeError: invalid SRE code.

…1665)

re.error is now raised instead of TypeError.

Macros Py_DECREF, Py_XDECREF, Py_IS_TYPE, _Py_atomic_load_32bit_impl
and _Py_DECREF_SPECIALIZED are redefined as macros
that completely replace the inline functions of the same name.
These three came out in the top four of functions that (in MSVC)
somehow weren't inlined.

Co-authored-by: Victor Stinner <vstinner@python.org>
Co-authored-by: Dennis Sweeney <36520290+sweeneyde@users.noreply.github.com>

…91817)

Closes GH-91764

Deprecate functions:

* PyUnicode_AS_DATA()
* PyUnicode_AS_UNICODE()
* PyUnicode_GET_DATA_SIZE()
* PyUnicode_GET_SIZE()

Previously, these functions were macros and so it wasn't possible to
decorate them with Py_DEPRECATED().