[MLton] Building MLton

[Vesa Karvonen]

Quoting John Skaller <skaller@users.sourceforge.net>:
> 1. Simple hack -- not good but it may get a result fastest:
>   use 'unsigned long' instead of 'unsigned int' for a word.
>   That's the same size as a pointer on gcc/x86-64 at the moment.
>   Downside: more storage for system 'integer' type.

I'm not entirely sure what you are after here, but, in C and C++, if you
want an (unsigned) integer type that is the same size as a pointer, you
should probably be using the (size_t) ptrdiff_t typedef.

-Vesa Karvonen