package.  If a Sym is a function symbol, include a reference
to the Func so it's easily accessible when you're traversing
the list of all symbols.  This diff is more interesting than
the proc switch because the gosym interface differs from the
old sym interface.

R=rsc
APPROVED=rsc
DELTA=1957  (34 added, 1868 deleted, 55 changed)
OCL=34969
CL=35008