PATCH v2: add mach-o handling in is32bit

[Nick Clifton]

Hi Tristan,

> bfd/:
> 2008-11-07  Tristan Gingold  <gingold@adacore.com>
> 
>     * bfd.c: Add BFD_VMA64 flag.
>     (is32bit): Return 0 if BFD_VMA64 flag is set.
>     * bfd-in2.h: Regenerate.
>     * mach-o.c (bfd_mach_o_scan): Set BFD_VMA64 if object file is 64bits.
>     (bfd_mach_o_object_p): Do not recognize 64bits files unless BFD64 is
>     defined.

Approved - please apply.

Cheers
   Nick