[kaffe] jnirefs.h - is this needed

[Michael Franz]

> Thanks to your question I have reread the JNI spec and it looks like we
> should on the contrary enable the JNI refs.
> They are not needed in most cases because we store objects on the stack
> but if the native call stores object in the heap we may lose track of
> used objects and garbage collects them though we should not. I don't
> know why they have been disabled by helmer (?)
> http://www.kaffe.org/cgi-bin/cvsweb/kaffe/kaffe/kaffevm/Attic/jnirefs.h.diff?r1=1.1&r2=1.2

Are we going to be enabling this?