Code in can_use_hardware_watchpoint()

[Michael Snyder]

Jim Blandy wrote:
> 
> I'm not really familiar with this code, but:
> 
> > One solution is to add an:
> >
> >       else if (v->lval == lval_register)
> >         return 0;
> 
> I think this is the right thing.

Yes, I'm going to add this change.