[PATCH] ada: Accept escaped '(' in a regular expression '()' group

[Samuel Tardieu]

On 25/07, Arnaud Charlet wrote:

| I can take care of it as part of regular submissions, although due to various
| build failures recently (and being on vacation before that), I have some
| back log, so won't get into it right away. I guess there's no real urgency
| in any case.

No urgency indeed, I found the bug by reading the code, this was not a
real-world problem.