Rebuilding error with unix-pthread in the intrp engine

[Erik Hu]

Hi Patrick 

I saw that "jthread_stackcheck" only declared in the following files.
~/system/beos-native/jthread.h
~/system/oskit-pthreads/jthread.h
~/system/unix-jthreads/jthread.h

Actually, there is no declared the "jthread_stackcheck" in
~/system/unix-pthreads/jthread.h file. I suppose it might be a bug in the
unix-ptherad for intrp engine.   

Is there any solution to fix the problem for unix-pthread for intrp
engine. ( I use the source code downloaded from www.kaffe.org. )

Many thanks. 

Regards,
Erik