[m-rev.] for review: start using pragma external_pred

[Zoltan Somogyi]

The diff is straightforward and does not need review. The only
thing worth reviewing is whether it is too early to start using
:- pragma external_pred, which was introduced almost exactly
one month ago.

Zoltan.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Log.external_pred
Type: application/octet-stream
Size: 432 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20150821/79565007/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DIFF.external_pred
Type: application/octet-stream
Size: 38007 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20150821/79565007/attachment-0001.obj>