Don't compile functions in a context the caller doesn't have access to

test/mjsunit/cross-realm-global-prototype.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax
+// Flags: --allow-natives-syntax --restricted-realms
 // Make sure we don't accidentally leak information about other objects.
 
 var realm = Realm.create();
 var test = Realm.eval(realm,
     "() => { return Realm.global(0) instanceof Object }");
 
 assertFalse(test());
 
 // Set the prototype of the current global object to the global object of the
 // other realm.
 __proto__ = Realm.eval(realm, "this");
 assertFalse(test());
 
 test();
 test();
 %OptimizeFunctionOnNextCall(test);
 assertEquals(false, test());