Implement ES5 erratum: global declarations shadow inherited properties.

src/objects.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 3007 matching lines @@
     object->GetIsolate(),
     object->SetLocalPropertyIgnoreAttributes(*key, *value, attributes),
     Object);
 }
 
 
 MaybeObject* JSObject::SetLocalPropertyIgnoreAttributes(
     String* name,
     Object* value,
     PropertyAttributes attributes) {
-
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc;
   Isolate* isolate = GetIsolate();
   LookupResult result(isolate);
   LocalLookup(name, &result);
   // Check access rights if needed.
   if (IsAccessCheckNeeded()) {
     if (!isolate->MayNamedAccess(this, name, v8::ACCESS_SET)) {
       return SetPropertyWithFailedAccessCheck(&result,
@@ skipping 48 matching lines @@
       return ConvertDescriptorToField(name, value, attributes);
     case CONSTANT_TRANSITION:
       // Replace with a MAP_TRANSITION to a new map with a FIELD, even
       // if the value is a function.
       return ConvertDescriptorToFieldAndMapTransition(name, value, attributes);
     case NULL_DESCRIPTOR:
     case ELEMENTS_TRANSITION:
       return ConvertDescriptorToFieldAndMapTransition(name, value, attributes);
     case HANDLER:
       UNREACHABLE();
-      return value;
   }
   UNREACHABLE();  // keep the compiler happy
   return value;
 }
 
 
 PropertyAttributes JSObject::GetPropertyAttributePostInterceptor(
       JSObject* receiver,
       String* name,
       bool continue_search) {
@@ skipping 9865 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal