Built-in JSON support

src/property.h

Index: src/property.h
diff --git a/src/property.h b/src/property.h
index 65d4a0d6d29705107a771ab842591c60600ce563..60a9b544deff24bfac8d8722b543b73af244b4ea 100644
--- a/src/property.h
+++ b/src/property.h
@@ -245,14 +245,25 @@ class LookupResult BASE_EMBEDDED {
   // Tells whether the value needs to be loaded.
   bool IsLoaded() {
     if (lookup_type_ == DESCRIPTOR_TYPE || lookup_type_ == DICTIONARY_TYPE) {
-      Object* value = GetValue();
-      if (value->IsJSFunction()) {
-        return JSFunction::cast(value)->IsLoaded();
-      }
+      Object* target = GetLazyValue();
+      return !target->IsJSObject() || JSObject::cast(target)->IsLoaded();
     }
     return true;
   }
 
+  Object* GetLazyValue() {
+    switch (type()) {
+      case FIELD:
+        return holder()->FastPropertyAt(GetFieldIndex());
+      case NORMAL:
+        return holder()->property_dictionary()->ValueAt(GetDictionaryEntry());
+      case CONSTANT_FUNCTION:
+        return GetConstantFunction();
+      default:
+        return Smi::FromInt(0);
+    }
+  }
+
   Map* GetTransitionMap() {
     ASSERT(lookup_type_ == DESCRIPTOR_TYPE);
     ASSERT(type() == MAP_TRANSITION);