[m-rev.] for review: document and test deconstruct_functor with infinity

[Zoltan Somogyi]

On Fri, 8 Jun 2018 16:27:53 +1000 (AEST), Julien Fischer <jfischer at opturion.com> wrote:
> +    % test infinite floats
> +    test_all(float.infinity, !IO),
> +    NegInf : float = -float.infinity,
> +    test_all(NegInf, !IO),
> +

The diff is fine, but I am wondering: what required the type qualification?

Zoltan.