Fix bootstrap on non-C99 systems

[Mark Mitchell]

Eric Botcazou wrote:
> The Fortran front-end now uses vsnprintf that, while being provided by 
> Libiberty, is not declared anywhere on non-C99 systems, thus causing a 
> bootstrap failure because of -Werror.
> 
> Fixed by the attached patch, bootstrapped/regtested on sparc-sun-solaris2.5.1 
> and x86_64-suse-linux, applied to mainline as obvious.

I think that the libiberty thinking is that in this situation the 
function ought to be declared in libiberty.h -- if no prototype appears 
in the system headers.  In other words, guarded with #ifndef 
HAVE_DECL_VNSPRINTF.  Making the fix in libiberty.h would help other 
uses of that library.  In C++, this is of course an error inependent of 
-Werror.

Before you work hard on a patch, you probably ought to get DJ or Ian to 
confirm my understanding.

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com
(916) 791-8304