Avoid reading RawObject::class_ directly in the runtime.

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index ee33853baf6f3c71912996bb473de29749bb771a..99e234e4906711948e1fa7608012c194b1d27f19 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -335,6 +335,7 @@ class RawObject {
 
   intptr_t GetClassIndex() const {
     uword tags = ptr()->tags_;
+    ASSERT(!FreeBit::decode(tags));

[Ivan Posva, 2012/06/01 16:31:06]

Please mark this with a TODO that we need to revisit this once we give the free
list elements a different layout.

     return ClassTag::decode(tags);
   }
 
@@ -344,6 +345,7 @@ class RawObject {
   friend class MarkingVisitor;
   friend class Object;
   friend class RawInstructions;
+  friend class RawInstance;
   friend class SnapshotReader;
   friend class SnapshotWriter;