[ic] Use validity cells to protect keyed element stores against object's prototype chain modificati…

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index e1347ffcefd5c63d298480f3aa9fd3e563183925..068ab034afbe1b585e112b490965195562c8909e 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -85,6 +85,9 @@ class V8_EXPORT_PRIVATE Factory final {
   // Create a new PrototypeInfo struct.
   Handle<PrototypeInfo> NewPrototypeInfo();
 
+  // Create a new Tuple2 struct.
+  Handle<Tuple2> NewTuple2(Handle<Object> value1, Handle<Object> value2);
+
   // Create a new Tuple3 struct.
   Handle<Tuple3> NewTuple3(Handle<Object> value1, Handle<Object> value2,
                            Handle<Object> value3);