fix alpha c++ failures

[John David Anglin]

> I'd rather we did the expansion via CONVERT_EXPR.  That lets us fold
> 
> > +	      new_bound = expand_binop (mode, sub_optab, new_high, new_low,
> >  				        NULL_RTX, unsignedp, OPTAB_WIDEN);
> 
> this one so that it generates no code.  Use type_for_mode to get the
> type to convert to.

I did check that this didn't generate any code on the PA and it seemed ok
in the one instance that I looked at.  However, I will try your suggestion.
It will be a useful learning experience.  I will let you know if the PA
problem can't be resolved in short order.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)