I just thought up this variant, I'm about to test it, but H.J., do you
see any problems with it?

#define itype(x) \
__typeof__(__builtin_choose_expr(sizeof(*(x)) > sizeof(0UL), 0ULL, 0UL))

I tried it out with a small test program (attached), and it seems to
work.  Next for using it in the kernel...

	-hpa