A question about tree-pretty-printing

[Richard Kenner]

    Doing something similar, with carets, is what prompted the writing
    of the new pretty-printer.  But I've long ignored the deficiency
    of tree-pretty-print.  Kenner said he has a patch.

A minor one, though.  I checked it in, but the spam filter on
gcc-patches ate it up.

I would really like to add a lang hook to deal with non-GENERIC nodes.
It would make the Ada .original dump look a little better, even though
I think there are only four such nodes at this point.