We only need to choose that we do want binning, or we don't.

We only need to choose that we do want binning, or we don't.
no need for multiple bin classes.  If multiple bins are needed, we
can always do it with ini type config instead.

kern/tru64/tru64_events.hh:
sim/system.cc:
sim/system.hh:
    No more GenBin always use MainBin

--HG--
extra : convert_revision : 8c466f302324c33b59d47d0da04583b2517fc72c