test_compiled_signature fails in Python 3.12 for next

[frenzymadness]

The failure is caused by the different signature for next builtin function:

>       assert signature.to_string() == sig
E       AssertionError: assert 'next()' == 'next(iterato...ault=None, /)'
E         - next(iterator, default=None, /)
E         + next()

This might actually be a problem in CPython because I've found some strange changes in help texts of some builtin functions as well. I've opened this issue: python/cpython#107526

What I don't understand is how Jedi gets signatures of builtin functions. inspect.signature does not work for builtins. Could you please help me understand how Jedi works here? It can help me find the right place in CPython to fix.

[davidhalter]

Jedi parses the __doc__ attribute, that's how it works. So either having a proper functioning inspect.signature or having a __doc__ in the format of builtins will make it possible for Jedi to have this kind of information.