[m-rev.] for post-commit review: move the report*stats predicates to benchmarking.m

[Julien Fischer]

On Mon, 7 Mar 2022, Zoltan Somogyi wrote:

> For review by anyone. The concept has been agreed and the
> move is straightforward. The things worth reviewing are the
> changes to NEWS, and the obsoleting of the impure, non-IO
> versions of the moved predicates.

I've committed a small correction to the NEWS file; the rest
looks fine.

Julien.