added 'isDenotable' flag to TypeConstructor

compiler/frontend/serialization/src/org/jetbrains/jet/descriptors/serialization/descriptors/DeserializedClassDescriptor.java

@@ -358,6 +358,11 @@ public class DeserializedClassDescriptor extends ClassDescriptorBase implements
             return !getModality().isOverridable();
         }
 
+        @Override
+        public boolean isDenotable() {
+            return true;
+        }
+
         @Nullable
         @Override
         public ClassifierDescriptor getDeclarationDescriptor() {

compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/descriptors/AbstractLazyTypeParameterDescriptor.java

@@ -168,6 +168,11 @@ public abstract class AbstractLazyTypeParameterDescriptor implements TypeParamet
                 return false;
             }
 
+            @Override
+            public boolean isDenotable() {
+                return true;
+            }
+
             @Override
             public ClassifierDescriptor getDeclarationDescriptor() {
                 return AbstractLazyTypeParameterDescriptor.this;

compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/descriptors/LazyClassDescriptor.java

@@ -478,6 +478,11 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements LazyDesc
             return !getModality().isOverridable();
         }
 
+        @Override
+        public boolean isDenotable() {
+            return true;
+        }
+
         @Override
         public ClassifierDescriptor getDeclarationDescriptor() {
             return LazyClassDescriptor.this;

compiler/frontend/src/org/jetbrains/jet/lang/types/IntersectionTypeConstructor.java

@@ -53,6 +53,11 @@ public class IntersectionTypeConstructor extends AnnotatedImpl implements TypeCo
         return false;
     }
 
+    @Override
+    public boolean isDenotable() {
+        return false;
+    }
+
     @Override
     public ClassifierDescriptor getDeclarationDescriptor() {
         return null;

compiler/frontend/src/org/jetbrains/jet/lang/types/TypeConstructor.java

@@ -34,6 +34,8 @@ public interface TypeConstructor extends Annotated {
 
     boolean isSealed();
 
+    boolean isDenotable();
+
     @Nullable
     ClassifierDescriptor getDeclarationDescriptor();
 }

compiler/frontend/src/org/jetbrains/jet/lang/types/TypeConstructorImpl.java

@@ -74,6 +74,11 @@ public class TypeConstructorImpl extends AnnotatedImpl implements TypeConstructo
         return sealed;
     }
 
+    @Override
+    public boolean isDenotable() {
+        return true;
+    }
+
     @Override
     @Nullable
     public ClassifierDescriptor getDeclarationDescriptor() {