[Patch, fortran-dev, committed] structural changes in the OOP implementation

[Janus Weil <janus at gcc dot gnu dot org>]

Hi all,

after our first round of OOP efforts had been merged to trunk a while
ago, I'm now re-opening the fortran-dev branch for further OOP work.

I have just committed as r153804 a patch which changes the basic
internal structure of the current OOP implementation, moving it into
the direction of vtables, which is necessary to achieve a fully
polymorphic OOP implementation. I will put some documentation of this
on http://gcc.gnu.org/wiki/OOP shortly.

Just as the earlier OOP stuff, this patch was mostly authored by Paul,
with some minor contributions by me and some testing by Salvatore and
Dominique (thanks, guys).

I will subsequently try to get my hands on stuff like CLASS IS in
SELECT TYPE and the EXTENDS_TYPE_OF intrinsic function, while Paul
will work on CLASS methods (i.e. polymorphic type-bound procedures),
which currently work only in certain limits (cf. e.g. PR41829).

Cheers,
Janus