Interceptors expect the receiver to always be an JSReceiver.

test/cctest/test-accessors.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 757 matching lines @@
   security_check_value = true;
   ExpectInt32("f()", 907);
   security_check_value = false;
   {
     v8::TryCatch try_catch(isolate);
     CompileRun("f();");
     CHECK(try_catch.HasCaught());
   }
 }
 
-static void check_receiver(Local<String> name,
-                           const v8::PropertyCallbackInfo<v8::Value>& info) {
+static void CheckReceiver(Local<String> name,
+                          const v8::PropertyCallbackInfo<v8::Value>& info) {
   CHECK(info.This()->IsObject());
 }
 
 TEST(Regress609134) {
-  v8::internal::FLAG_allow_natives_syntax = true;
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   v8::HandleScope scope(isolate);
   auto fun_templ = v8::FunctionTemplate::New(isolate);
   fun_templ->InstanceTemplate()->SetNativeDataProperty(v8_str("foo"),
-                                                       check_receiver);
+                                                       CheckReceiver);
 
   CHECK(env->Global()
             ->Set(env.local(), v8_str("Fun"),
                   fun_templ->GetFunction(env.local()).ToLocalChecked())
             .FromJust());
 
   CompileRun(
       "var f = new Fun();"
       "Number.prototype.__proto__ = f;"
       "var a = 42;"
       "for (var i = 0; i<3; i++) { a.foo; }");
 }