tSubType fix for top == Unknown

git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@86 379699f6-c40d-0410-875b-85095c16579e

jode/jode/type/Type.java

@@ -190,8 +190,12 @@ public class Type {
     }
 
     public static Type tSuperType(Type type) {
+        if (type.getTop() == tUnknown) {
             if (type == tBoolInt || type == tBoolByte)
                 return tBoolInt;
+            if (type.getBottom().typecode == TC_CLASS)
+                return tUObject;
+        }
         return type.getTop().createRangeType(tUnknown);
     }