RFC: replace vm_offset_t with uintptr_t and vm_size_t with size_t

[mdf at FreeBSD.org]

Looking over the arch-specific definitions, using uintptr_t and size_t
would not affect the actual width of these sizes.  However, it would
simplify e.g. conformant printf(9) statements, since there is an
approved specifier for size_t and, while there isn't one for
uintptr_t, ptrdiff_t is pretty close (Bruce, is there a better
specifier)?

Admittedly, this isn't the simplest of undertakings, as there are 590
instances of vm_size_t in the FreeBSD source code and 3887 of
vm_offset_t.

Has this proposal made the rounds before and been shot down for some reason?

Thanks,
matthew