[testsuite, ada] Convert ACATS to DejaGnu (PR testsuite/37703)

[Arnaud Charlet]

> I think the most progress will be made the fastest, when you just start
> putting it in the tree with it on, or both on.  The only problem with that right
> now, is the poor timing wrt the release.  If you can build consensus with the
> Ada people and possibly the RMs on timing issues, you could run experiments
> in trunk, but...  I think I'd say don't even try.

Right, my feeling is that this kind of change is really more suitable for
stage1 rather than stage4.

> The Ada people will have to weigh in on the addition of -O2 to the files in the
> testsuite.

I haven't seen this part, are we talking about changing a couple of files or
changing hundreds of files?

If a couple of files, then that's OK. If we're talking about hundreds of
files, then that's not a good idea.

Arno