Improve printing for Symbols.

src/objects-printer.cc

 // Copyright 2012 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.
 
 #include "src/v8.h"
 
 #include "src/disasm.h"
 #include "src/disassembler.h"
 #include "src/heap/objects-visiting.h"
 #include "src/jsregexp.h"
@@ skipping 409 matching lines @@
   }
   UNREACHABLE();
   return "UNKNOWN";  // Keep the compiler happy.
 }
 
 
 void Symbol::SymbolPrint(std::ostream& os) {  // NOLINT
   HeapObject::PrintHeader(os, "Symbol");
   os << " - hash: " << Hash();
   os << "\n - name: " << Brief(name());
+  if (name()->IsUndefined()) {
+    os << " (" << PrivateSymbolToName() << ")";
+  }
   os << "\n - private: " << is_private();
   os << "\n - own: " << is_own();
   os << "\n";
 }
 
 
 void Map::MapPrint(std::ostream& os) {  // NOLINT
   HeapObject::PrintHeader(os, "Map");
   os << " - type: " << TypeToString(instance_type()) << "\n";
   os << " - instance size: " << instance_size() << "\n";
@@ skipping 677 matching lines @@
     }
   }
   os << "\n";
 }
 
 
 #endif  // OBJECT_PRINT
 
 
 } }  // namespace v8::internal