Document __builtin_*_overflow

[Jakub Jelinek]

On Wed, Nov 12, 2014 at 03:39:25PM +0100, Tristan Gingold wrote:
> 
> > On 12 Nov 2014, at 14:13, Jakub Jelinek <jakub@redhat.com> wrote:
> > +  size_t sz;
> > +  if (__builtin_mul_overflow (x, y, &sz)
> 
> Missing right parenthesis ?

Thanks, fixed.

	Jakub