#2 Cf: Incomplete support for U64 on 32-bit CPU

[james woodyatt]

In environments where the compiler does not handle 'unsigned long
long' internally, the OCaml runtime environment has a workaround.
The Cf library doesn't understand this workaround.

But it may never have to— are there any supported environments
where a C compiler still doesn't understand "unsigned long long" as
64-bit integer on an ILP32 architecture? I don't think so...