[m-rev.] for post-commit review: fix mantis bug 410

[Julien Fischer]

Hi Zoltan,

On Sat, 17 Jun 2017, Zoltan Somogyi wrote:

> For post-commit review by anyone.
>
> The error messages we now generate for the test case
> are not particularly pretty, but they are better than the
> compiler crash that we used to get before this diff.
>
> A question for everyone. When a predicate has no
> type declaration (either because it is missing, or because
> it has a syntax error, as in the regression test in this diff),
> should we suppress the generation of the error message
> about the predicate having no mode declarations either?

I think we should.

The diff looks fine.

Julien.