Allow users of the V8 API to distinguish between unset and undefined HiddenValues

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 2e2a01845b7661696bc4fb841701891526d5d4eb..d3abed115be674d2c292ab2b50c0a880f03f8a0f 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1996,7 +1996,7 @@ class JSObject: public JSReceiver {
                                           Handle<Object> value);
   // Returns a failure if a GC is required.
   MUST_USE_RESULT MaybeObject* SetHiddenProperty(Name* key, Object* value);
-  // Gets the value of a hidden property with the given key. Returns undefined
+  // Gets the value of a hidden property with the given key. Returns the hole
   // if the property doesn't exist (or if called on a detached proxy),
   // otherwise returns the value set for the key.
   Object* GetHiddenProperty(Name* key);