[m-rev.] multi-precision integers based on GMP

[Matthias Güdemann]

Hi Julien,

> I've had a quick glance through the pull request; one thing you should
> do is set the 'can_pass_as_mercury_type' attribute on the foreign type
> pragma for the type gmp_int/0.  In the absence of that attribute the
> compiler may box values of that type.

ok, done. Thanks for the hint. I found an old thread from 2011 where you
stated that this is in practice always done for foreign types
represented as C pointers.

Best regards,
Matthias