DamageMobj can destroy the damaged actor if the death state sequence has zero duration. But Actor.target is a garbage collected member variable, i.e. it will be null, once the actor it points to gets destroyed.
This was originally done correctly in the C++ code but during the scriptification all those 'AActor *target = self->target' lines were removed because they looked redundant, but were not.
- fixed emission of the self pointer in FxVMFunctionCall. I did not realize that the self expression only sets up a register for the value, not pushing it onto the stack.
