bug#25987: 25.2; support gcc fixit notes

[Dmitry Gutov]

On 09.03.2017 20:32, Eli Zaretskii wrote:

> > > It sounds gross to ask people to use Flymake just to be able to use
> > > something like this.
> >
> > What's gross about that?
>
> It's a large package, and its purpose is not just fix compilation
> errors.

Its purpose is just showing them, and we, ideally, need both.

Flymake is moderately large because it includes some checker 
definitions. We could extract the core to a separate file.

Anyway, yes, a minor mode that would act on the fixits inside the 
Compilation buffer might be helpful.

But that's basically ignoring the prior art in IDEs that you asked 
about, where "quick fixes" go together with in-buffer visualizations.