Disallow Object.observe calls on access-checked objects

src/runtime/runtime-object.cc

Index: src/runtime/runtime-object.cc
diff --git a/src/runtime/runtime-object.cc b/src/runtime/runtime-object.cc
index 75d09a8ee70598931332ce4213b161fba036244c..9ca77764e8159a6f7b2e9079dad47b659b0d259b 100644
--- a/src/runtime/runtime-object.cc
+++ b/src/runtime/runtime-object.cc
@@ -1551,5 +1551,14 @@ RUNTIME_FUNCTION(Runtime_CreateIterResultObject) {
   return *isolate->factory()->NewJSIteratorResult(value, done);
 }
 
+
+RUNTIME_FUNCTION(Runtime_IsAccessCheckNeeded) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(Object, object, 0);
+  return isolate->heap()->ToBoolean(object->IsAccessCheckNeeded());
+}
+
+
 }  // namespace internal
 }  // namespace v8