Fix compiler warnings

[Jakub Jelinek]

On Wed, May 06, 2015 at 06:18:23PM +0200, Marek Polacek wrote:
> On Wed, May 06, 2015 at 04:58:03PM +0200, Jakub Jelinek wrote:
> > Also, it would be nice to figure why gcc doesn't warn (for both meaningful
> > changes, in the first snippet I believe gcc just determines the static
> > function is noreturn and that is why it correctly doesn't warn).
> > I thought Marek has added patches for the !x == Y case recently, so it would
> > be nice to find out why we don't warn in that case.
> 
> Yes, I'd expect a warning to trigger on that.
>  
> > Similarly for the bool case, does clang warn on +/++ operation on bool (which
> > is well defined, supposedly it should be some style warning?), or something
> > else?
> 
> clang++ warns for
>   bool b = false;
>   b++;
> but not for
>   bool b = false;
>   b += 2;

As both are just fancy ways of b = true;, supposedly we want to warn on
both. The question is under which -W* option, and whether to include it even
in -Wall, or just in -W.

	Jakub