determinstic order of LDTs, fix assertion

Author: wadoon

key.core/src/main/java/de/uka/ilkd/key/java/TypeConverter.java

@@ -7,6 +7,7 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.TreeMap;
 
 import de.uka.ilkd.key.java.abstraction.*;
 import de.uka.ilkd.key.java.expression.Literal;
@@ -41,7 +42,7 @@ public final class TypeConverter {
     private final Services services;
 
     // Maps LDT names to LDT instances.
-    private final Map<Name, LDT> LDTs = new HashMap<>();
+    private final Map<Name, LDT> LDTs = new TreeMap<>();
 
     private HeapLDT heapLDT = null;
     // private IntegerLDT integerLDT = null;

key.core/src/main/java/de/uka/ilkd/key/ldt/JavaDLTheory.java

@@ -151,7 +151,6 @@ public final SortDependingFunction getExactInstanceofSymbol(Sort sort, TermServi
     @Override
     public boolean isResponsible(Operator op, JTerm[] subs, Services services,
             ExecutionContext ec) {
-        assert false;
         return false;
     }