[m-rev.] for review: improve messages for some mode errors

[Peter Wang]

On Fri, 24 Jan 2020 04:54:10 +1100 (AEDT), "Zoltan Somogyi" <zoltan.somogyi at runbox.com> wrote:
> For review by anyone.
> 
> Zoltan.
> Improve error messages for some mode errors.
> 

> diff --git a/tests/invalid/any_passed_as_ground.err_exp b/tests/invalid/any_passed_as_ground.err_exp
> index 4a87a3d66..9dd15afae 100644
> --- a/tests/invalid/any_passed_as_ground.err_exp
> +++ b/tests/invalid/any_passed_as_ground.err_exp
> @@ -6,4 +6,6 @@ any_passed_as_ground.m:029:     free,
>  any_passed_as_ground.m:029:     any
>  any_passed_as_ground.m:029:   which does not match any of the modes for
>  any_passed_as_ground.m:029:   predicate `list.member'/2.
> +any_passed_as_ground.m:029:   The second argument `Xs', whose inst is `any',
> +any_passed_as_ground.m:029:   does not match any of those modes.

Slightly simpler wording?

    The second argument `Xs' has inst `any',
    which does not match any of those modes.

Peter