%fyrd is now implemented in terms of %fard, and likewise %avow in terms
of %arow. State is tracked via wire rather than in a global map.
Unit tests adjusted to match.
These take and produce vases, and assign random tids (rather than
deducing them from the input duct.)
Since %fard does not require mark conversion, we make the mark/beak on
$thread-state optional (and use this to decide whether to send %avow or
%arow.) Provide a state adapter since it's possible that people have
been experimenting with this vane.
This makes the negative case of %avow/%arow kind of clunky, since there
is no content difference, but the following does not seem possible
within the Hoon type system:
=/ gif
?~ p.tad
%arow %avow
[hen %give gif %| p.cag tang]~
- only store metadata in the persistent map. just enough to support
(eventual) thread cancellation and output mark lookup.
- try to delete thread state at other failure points not covered by
%kick.
- reflect back the passed output mark rather than form.dais. not sure
about this one yet.
