[PATCH 0/3] Clarify built-in library/SRFI feature behaviour

[Evan Hanson]

Hi folks,

After thinking about #1788 a little bit more I've came up with a few
small "code clarity" patches. They don't change the existing solution at
all, they're just to simplify the code after looking at it with fresh
eyes. Partly, I realised the naming of that "required-libraries" wasn't
great, but I also liked that I'd originally been able to simplify
`##sys#process-require` so it only returned a single value, and wanted
to see if we could preserve that. I think the result is nice and tidy,
see if you agree.

Looking into this also made me realise that all of the short-circuiting
we do when handling require forms for built-in libraries wasn't actually
necessary, since we can avoid hitting that code path altogether by
simply not adding libraries for those, which is patch number two.

And then, once I was already down that rabbit hole, I went through all
of the SRFI-related feature identifiers to make sure they were
registered in the right files, and that the documentation was up to
date. That's patch number three, have a look and let me know what you
think.

All the best,

Evan

0001-Simplify-library-requirement-processing.patch
Description: Text document

0002-Make-primitive-modules-avoid-triggering-any-code-loa.patch
Description: Text document

0003-Update-SRFI-feature-identifiers-and-documentation.patch
Description: Text document