[strong] Strong classes can't extend null

src/messages.h

 // Copyright 2006-2008 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.
 
 // The infrastructure used for (localized) message reporting in V8.
 //
 // Note: there's a big unresolved issue about ownership of the data
 // structures used by this framework.
 
 #ifndef V8_MESSAGES_H_
@@ skipping 212 matching lines @@
   T(StrictCannotAssign, "Cannot assign to read only '% in strict mode")        \
   T(StrictDeleteProperty, "Cannot delete property '%' of %")                   \
   T(StrictPoisonPill,                                                          \
     "'caller', 'callee', and 'arguments' properties may not be accessed on "   \
     "strict mode functions or the arguments objects for calls to them")        \
   T(StrictReadOnlyProperty, "Cannot assign to read only property '%' of %")    \
   T(StrongArity,                                                               \
     "In strong mode, calling a function with too few arguments is deprecated") \
   T(StrongDeleteProperty,                                                      \
     "Deleting property '%' of strong object '%' is deprecated")                \
+  T(StrongExtendNull, "In strong mode, classes extending null are deprecated") \
   T(StrongImplicitConversion,                                                  \
     "In strong mode, implicit conversions are deprecated")                     \
   T(StrongRedefineDisallowed,                                                  \
     "On strong object %, redefining writable, non-configurable property '%' "  \
     "to be non-writable is deprecated")                                        \
   T(StrongSetProto,                                                            \
     "On strong object %, redefining the internal prototype is deprecated")     \
   T(SymbolKeyFor, "% is not a symbol")                                         \
   T(SymbolToPrimitive,                                                         \
     "Cannot convert a Symbol wrapper object to a primitive value")             \
@@ skipping 211 matching lines @@
 
   static void DefaultMessageReport(Isolate* isolate, const MessageLocation* loc,
                                    Handle<Object> message_obj);
   static Handle<String> GetMessage(Isolate* isolate, Handle<Object> data);
   static SmartArrayPointer<char> GetLocalizedMessage(Isolate* isolate,
                                                      Handle<Object> data);
 };
 } }  // namespace v8::internal
 
 #endif  // V8_MESSAGES_H_