bug#15880: Compute C declarations for DEFSYMs automatically.

[Eli Zaretskii]

> Date: Thu, 14 Nov 2013 12:25:45 -0800
> From: Paul Eggert <eggert@cs.ucla.edu>
> CC: monnier@iro.umontreal.ca, 15880@debbugs.gnu.org
> 
> Since there are quite a few symbols it might be worth doing this
> only when -g3 is not used, to keep the runtime a bit smaller.

That would be confusing, I think.  We shouldn't need to remember how
Emacs was compiled to debug it.  Having a "print Qfoo" display some
weird error message under obscure circumstances is an annoyance.