bug#68272: [PATCH] Fix -1 leaking from C to lisp in 'read-event' etc.

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Eli Zaretskii <eliz@gnu.org>,  68272@debbugs.gnu.org
> Date: Tue, 05 Mar 2024 11:45:41 -0500
> 
> Eli Zaretskii [2024-03-05 15:10:39] wrote:
> > IOW, what about callers that actually _want_ to know when the macro
> > ends prematurely?
> 
> I couldn't find any, really.

??? calc is one, obviously.

> > +     t = 0;
> > +     /* The Microsoft C compiler can't handle the goto that
> > +        would go here.  */
> > +     dummyflag = true;
> > +     break;
> > +   }
> 
> This "Microsoft C compiler" business dates back to 1994 (commit
> bc536d847736f466727453ca6aa7c07aef6fce46).
> I think it's safe to clean it up now :-)

The commit and its date don't matter, since we dropped support for
MSVC long ago.  We only support GCC on Windows (at least officially).