[antlr-interest] Exit Status from ANTLR

[Robin Davies]

> >> I want an exit status from the ANTLR parser generator tool, not
> >> from the parsers it generates.
> >

Although an error count in the runtime would be nice too. At this point, I 
can't imagine that anyone is NOT going to have to find the right error 
message function in parsers and/or lexers to override just so that they can 
go ++Error, just so that they can return failures when running generated 
grammars.  (Is this a C# runtime thing, or do all runtimes suffer from 
that?)