A class has an assignment where the target entity is of an expanded
type and the source entity is of an expanded type which inherits
(indirectly) from the target type base class, but adds some
attributes.  After initial compilation where the system is melted, the
type of the source entity is changed to another expanded type which is
a parent of the original source entity type and the system is frozen.
System execution then ends with a segmentation fault.

Discovered in Release 3.2.3b.