Warn about recursively calling size req wrappers on the same object and orientation

Warn about recursively calling size req wrappers on the same object and orientation

We are not re-entrant and there is no reason for widgets to
do this, most likely they'll just get unexpected bugs because
the wrappers may modify the request.

Computing the request should logically rely only on the
widget itself, not on any adjustments caused by set_size_request,
size groups, and so forth.

https://bugzilla.gnome.org/show_bug.cgi?id=628829