> I suppose we could change the 64-bit MACHINE_ARCH to `sparcv9' but
	> that would cause certain disruption.

	That would also solve the problem, as long as you never build with
	MACHINE == sparc, MACHINE_ARCH == sparc64.

That wouldn't work too well since 32-bit sparcs cannot execute 64-bit
intstructions.  So it would have to be a cross-build environment and
in that case you would explicitly set both MACHINE and MACHINE_ARCH
to sparc64.

Eduardo