[RFA] Add some code in observer.c to allow unit-testing

[Joel Brobecker]

> Long term, it's going to run into -Wunused-function.  Suggest adding a 
> disclaimer pointing out this limitation :-)

Sure, I added the following comment:

/* Since this code will not be used within GDB, it will trigger
   a warning if we decide to compile with -Wunused-function.
   This is ok for now.  (brobecker 2003-03-18)  */

> Otherwize (for want of any beter idea :-), ok.

Checked in, with the above addition.

Thanks,
-- 
Joel