Track representations of fields

src/property.h

Index: src/property.h
diff --git a/src/property.h b/src/property.h
index bbba8aea60d89f432c3ca4eb52b86726e56baf07..1e68c5f4102738c02588235887cde50199b561b3 100644
--- a/src/property.h
+++ b/src/property.h
@@ -65,11 +65,17 @@ class Descriptor BASE_EMBEDDED {
 #endif
 
   void SetEnumerationIndex(int index) {
+    StorageType storage = details_.storage_type();
     details_ = PropertyDetails(details_.attributes(), details_.type(), index);
+    details_ = details_.set_storage_type(storage);
   }
 
   void SetSortedKeyIndex(int index) { details_ = details_.set_pointer(index); }
 
+  void SetStorageType(StorageType storage) {
+    details_ = details_.set_storage_type(storage);
+  }
+
  private:
   Name* key_;
   Object* value_;
@@ -208,6 +214,10 @@ class LookupResult BASE_EMBEDDED {
     number_ = number;
   }
 
+  bool CanStore(Handle<Object> value) {
+    return value->FitsStorage(details_.storage_type());
+  }
+
   void TransitionResult(JSObject* holder, int number) {
     lookup_type_ = TRANSITION_TYPE;
     details_ = PropertyDetails(NONE, TRANSITION);
@@ -256,6 +266,11 @@ class LookupResult BASE_EMBEDDED {
     return details_.type();
   }
 
+  StorageType storage_type() {
+    ASSERT(IsFound());
+    return details_.storage_type();
+  }
+
   PropertyAttributes GetAttributes() {
     ASSERT(!IsTransition());
     ASSERT(IsFound());