Provide private symbols through internal APIs

src/objects-debug.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 224 matching lines @@
   CHECK(p->IsHeapObject());
   HeapObject* ho = HeapObject::cast(p);
   CHECK(ho->GetHeap()->Contains(ho));
 }
 
 
 void Symbol::SymbolVerify() {
   CHECK(IsSymbol());
   CHECK(HasHashCode());
   CHECK_GT(Hash(), 0);
-  CHECK(name()->IsUndefined() || name()->IsString());
+  CHECK(name()->IsUndefined() || name()->IsString() || name()->IsBox());
+  if (IsPrivate()) {
+    CHECK(Private::cast(this)->name()->IsUndefined() ||
+          Private::cast(this)->name()->IsString());
+  }
 }
 
 
 void HeapNumber::HeapNumberVerify() {
   CHECK(IsHeapNumber());
 }
 
 
 void ByteArray::ByteArrayVerify() {
   CHECK(IsByteArray());
@@ skipping 943 matching lines @@
   for (int i = 0; i < number_of_transitions(); ++i) {
     if (!CheckOneBackPointer(current_map, GetTarget(i))) return false;
   }
   return true;
 }
 
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal