fix a +has:in call site
|= [acc=_map [ty=type k=xkey]]
=/ dest (~(get by refs.tbl) k)
?^ dest (~(put by acc) ty u.dest)
- ?. (~(has in live.tbl)) acc
+ ?. (~(has in live.tbl) k) acc
(~(put in acc) ty k)
::
:: Rebuild the `xrays` table.
