[Patch] Fix for PR9812

[Erik Verbruggen]

> On Sat, Dec 14, 2013 at 5:31 AM, Erik Verbruggen <erik.verbrug... at me.com> wrote:
> > This is a fix for PR9812, and I have to say that I don't know what more to 
> > say in the commit message than "warn about bool instead of _Bool", so 
> > feedback is welcome! I sometimes run into this, hence the patch.
> >
> > Two notes: I have to say that the patch feels a bit intrusive, but I didn't 
> > find a better way to do this. Also, in MS mode, it will warn about __wchar_t 
> > v.s. wchar_t. I haven't extensively tested this on Windows, but to me it 
> > looks like the correct thing. Again, feedback welcome!
> 
> Thank you for working on this!  This is a strict improvement for C++,
> the issue still remains for C.  In that case, we should do something
> like Sema::getPrintingPolicy().  We should not be printing 'bool' in C
> unless the said macro exists -- we need tests for both cases.  Will
> you fix the C case as well?

I can do that. Should I do that in a separate commit, or should I do it in this patch?

-- Erik