+ * 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.
+
+ + 28.6.04 MMB
+ Div/Mod optimization for constants produces a result that will be optimized
+ again and again :-( Add a flag or a clever encoding so thios does not happen
+ Goetz 10.6.04
Error in removing dead code: