Make Type, TypeParameter, TypeArguments and InstantiatedTypeArguments final heap objects.

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 17737)
+++ runtime/vm/object.h	(working copy)
@@ -1076,7 +1076,7 @@
   RawAbstractType** TypeAddr(intptr_t index) const;
   void SetLength(intptr_t value) const;
 
-  HEAP_OBJECT_IMPLEMENTATION(TypeArguments, AbstractTypeArguments);
+  FINAL_HEAP_OBJECT_IMPLEMENTATION(TypeArguments, AbstractTypeArguments);
   friend class Class;
 };
 
@@ -1131,7 +1131,8 @@
       const AbstractTypeArguments& value) const;
   static RawInstantiatedTypeArguments* New();
 
-  HEAP_OBJECT_IMPLEMENTATION(InstantiatedTypeArguments, AbstractTypeArguments);
+  FINAL_HEAP_OBJECT_IMPLEMENTATION(InstantiatedTypeArguments,
+                                   AbstractTypeArguments);
   friend class Class;
 };
 
@@ -3558,7 +3559,7 @@
 
   static RawType* New(Heap::Space space = Heap::kOld);
 
-  HEAP_OBJECT_IMPLEMENTATION(Type, AbstractType);
+  FINAL_HEAP_OBJECT_IMPLEMENTATION(Type, AbstractType);
   friend class Class;
 };
 
@@ -3618,7 +3619,7 @@
   void set_type_state(int8_t state) const;
   static RawTypeParameter* New();
 
-  HEAP_OBJECT_IMPLEMENTATION(TypeParameter, AbstractType);
+  FINAL_HEAP_OBJECT_IMPLEMENTATION(TypeParameter, AbstractType);
   friend class Class;
 };