Re: Simple recompute_reg_usage cleanup

[Jan Hubicka <hubicka at atrey dot karlin dot mff dot cuni dot cz>]

> > The VTOP notes only seem to be used by loop.c and reorg.c and in both
> > cases they are only used to guess program flow which we can determine
> > more accurately from the CFG.
> 
> No, loop also wants to know if the loop condition has already been evaluated
> for the first iteration, yielding true.
> I.e. VTOP also says something about the range of values that the
> iteration varaible can hold.
> 
Aha. 
What prevents us from doing the exit test duplication after loop?
(I.e remove it from jump pass and do it as the last think in loop pass?)
(quick searching says that jump is the only setter of this note, so
this ought not to be problem)

Honza