[es6] silence access-check failure for well-known symbol properties

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 2b072f302144b48a82ee29453d60fc813de2ae5d..efcadf5c5ece278ad60ac147d55e7b99273a7234 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -2662,6 +2662,7 @@ void Heap::CreateInitialObjects() {
     HandleScope scope(isolate());
 #define SYMBOL_INIT(name, description)                                      \
   Handle<Symbol> name = factory->NewSymbol();                               \
+  name->set_is_well_known_symbol(true);                                     \
   Handle<String> name##d = factory->NewStringFromStaticChars(#description); \
   name->set_name(*name##d);                                                 \
   roots_[k##name##RootIndex] = *name;