Re: Enabling --enable-check-lisp-object-type by default on x86 and AMD64

[Eli Zaretskii <eliz@gnu.org>]

> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Tue, 2 May 2017 15:14:17 -0700
> Cc: Emacs developers <emacs-devel@gnu.org>
> 
> For x86-64 there should be little difference nowadays when 
> --enable-check-lisp-object-type is used. For other platforms (e.g., 
> x86), however, I suppose there can still be a significant (though small) 
> difference. So when compiling emacs for production, it makes sense to 
> omit --enable-check-lisp-object-type, for the benefit of x86 and similar 
> platforms.
> 
> When developing, the advantages of --enable-check-lisp-object-type 
> outweigh the small increase in runtime cost, particularly considering 
> that x86-64 is the most common development platform nowadays and there 
> the runtime cost is insignificant.  So it makes sense to default 
> --enable-check-lisp-object-type to "yes" if --enable-gcc-warnings is 
> also enabled (which it is by default, in developer builds). I did this 
> by installing the attached patch; comments welcome.

One difficulty this adds in developing is that backtraces are much
less readable, as Lisp_Object values are not shown.