32->64 bit cross compilers

[Richard Kenner]

    To me it is pretty important to be able to do Linux->Sparc 64 cross
    compilation at least, since this (along with NT->Sparc 64) is a likely
    desired combination.

Right, but we're talking about the *branch* here, not the mainline.
My point was that this never really worked in the past, we shouldn't
risk destabilizing the branch to make it work there now.  I agree this is
important for the mainline.