Moving issues to GitHub

Hi everyone,

I'd like to propose that the issues for the language specification be moved
from bugs.php.net to GitHub Issues. I realize that the usual php.net policy
is to avoid the use of GH issues, but I think there are good reason to not
use bugs.php.net for the language specification, in particular:

1. I think the spec would benefit from the ability to quickly record minor
deficiencies (like "incorrect precedence for print expression"). There are
currently some people using the language specification to guide
implementation and, of course, this often results in minor errors being
found. However, these errors never make it to bugs.php.net. Instead, they
are either PRed directly (good) or, quite commonly, lost in the comments of
a 3rd party repository (bad). I think this has a lot to do with bugs.php.net
being a bad interface for this purpose.

2. Anyone who is subscribed to this list will know that maybe 90% of all
bugs submitted under the "Language Specification" category on bugs.php.net
are bogus. They are being used as a general PHP feature request category,
rather than a place to report issues with the specification. Presumably,
moving to GitHub issues would avoid this issue, because the issues would be
located in the langspec repo, rather than a general purpose PHP bugtracker.

If we do this, I will update the GH webhook that is currently sending PRs
to this list to also send Issues here.

Regards,
Nikita