Implement tracking and optimizations of packed arrays.

src/api.h

Index: src/api.h
diff --git a/src/api.h b/src/api.h
index 3ad57f465763a740a70b9fbd5d6fa189c4518ead..4be1b2be0e18fc21b91d46d16d9e6d04675d9557 100644
--- a/src/api.h
+++ b/src/api.h
@@ -105,13 +105,13 @@ NeanderArray::NeanderArray(v8::internal::Handle<v8::internal::Object> obj)
 
 
 v8::internal::Object* NeanderObject::get(int offset) {
-  ASSERT(value()->HasFastElements());
+  ASSERT(value()->HasFastSmiOrObjectElements());
   return v8::internal::FixedArray::cast(value()->elements())->get(offset);
 }
 
 
 void NeanderObject::set(int offset, v8::internal::Object* value) {
-  ASSERT(value_->HasFastElements());
+  ASSERT(value_->HasFastObjectElements());
   v8::internal::FixedArray::cast(value_->elements())->set(offset, value);
 }