Warnings not removed with reluctant destabilization and incremental postsolving

[sim642]

@vesalvojdani reported that with both reluctant destabilization and incremental postsolving enabled, warnings from changed functions are not removed when the issue is fixed.

The underlying problem is likely that reluctant destabilization only destabilizes the function return node (if changed), but not its entry node (as with non-reluctant destabilization). Therefore the old body of the function remains stable and notably superstable, so warnings are reused during incremental postsolving.

Solutions

The possible solutions are:

1. Use delete_marked on more TD3 solver data structures, notably superstable, to remove warnings from the old copy.

   This should suffice because the lack of delete_marked on new data structures is probably just an oversight from when they were added.

2. Destabilize old non-entry nodes (not just return node), so they are removed from superstable.