+ * 27.8.2004 Goetz
+ Classes need a flag comparable to visibility of entities.
+ This flag must express whether these classes are accessed from
+ outside, i.e., the fields must have a specific layout.
+ Further it should express whether the outside can allocate classes
+ of the type. Then we can determine whether the class can be turned
+ into a description class by, e.g., rta.
+
+ *
+
* 5.7.04 Goetz
in free_type: check the types that there is no pointer type that points
to the freed type. If so report error.