[V] Support builtin functions in find-function (crash in C-h f)

[Aidan Kehoe]

 Ar an triochadú lá de mí Aibréan, scríobh Aidan Kehoe: 

 >  > By the way, there are changes in src/symbols.c and src/sysfile.h that
 >  > aren't in the ChangeLog.  I assume these are due to your commit.
 > 
 > They are; I had thought I had committed them already, because they weren’t
 > appearing in cvs diff for some reason. 

I’ve added documentation of those changes to the ChangeLog. 

-- 
Aidan Kehoe, http://www.parhasard.net/