[Python-Dev] PEP 580 (C call protocol) minor update

[Jeroen Demeyer]

I made some minor updates to PEP 580 (PEP editors: please merge 
https://github.com/python/peps/pull/741) and its reference implementation:

- Added a new introductory section explaining the basic idea.

- The C protocol no longer deals with __name__; a __name__ attribute is 
required but the protocol does not deal with its implementation.

- The PEP no longer deals with profiling. This means that profiling only 
works for actual instances of builtin_function_or_method and 
method_descriptor. Profiling arbitrary callables would be nice, but that 
is deferred to a future PEP.

The last two items are meant to simplify the PEP (although this is 
debatable since "simple" is very subjective).


Enjoy!
Jeroen.