[m-rev.] for review: reorder the contents of map.m

[Zoltan Somogyi]

On Fri, 31 Jan 2020 11:22:24 +1100 (AEDT), Julien Fischer <jfischer at opturion.com> wrote:
> > The attached diff isn't complete, since it needs a NEWS entry,
> > but there is as yet no NEWS section for changes *since* 20.01.
> > Can you please add one? If you don't want to add it empty,
> > you can add a description of this diff.
> 
> Done.

Thanks.

I changed the listing of new things from

- keys_as_set/1
- keys_as_set/2

to

- func keys_as_set/1
- pred keys_as_set/2

since I think this is much clearer. Can we all agree to always specify
func vs pred in similar entries in the future?

Zoltan.