32->64 bit cross compilers

[Richard Kenner]

    I think that we have to support 32->64 bit cross compilers in GCC 3.0,
    so I think these patches should go in.

I think it would be *nice*, but I don't think we "have to".  This never
really worked right due to config files that didn't properly check
the bounds of constants, mostly in the older machines.  So I don't
think it's so terrible if it still doesn't, especially since changes to
fix these things can easily cause instability.