forbid extending sort K in the Java backend

Fixed https://github.com/kframework/k/issues/708

@dwightguth @radumereuta please review
It's commented per our discussion yesterday. I'm working on fixing it.


2014-07-16 18:09 GMT+03:00 dwightguth <notifications@github.com>:

> In tests/regression/java-rewrite-engine/config.xml:
>
> > @@ -278,9 +278,9 @@
> >        <krun-option name="--smt" value="none" />
> >      </all-programs>
> >    </test>
> > -
> > +<!--
>
> what? no, why are we commenting out this test? If you intend to
> immediately fix it, fix it first and /then/ merge. Commenting it out now
> runs the risk of introducing regressions from another change during the
> time it's commented out.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/kframework/k/pull/714/files#r15003212>.
>