fix -Wunused-but-set-variable for gcc-4.6 on x64

src/objects.cc

 // Copyright 2011 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 2202 matching lines @@
   Handle<Object> trap(v8::internal::GetProperty(handler, trap_name));
   if (trap->IsUndefined()) {
     trap = isolate->derived_set_trap();
   }
 
   // Call trap function.
   Object** args[] = {
       receiver.location(), name.location(), value.location()
   };
   bool has_exception;
-  Handle<Object> result =
-      Execution::Call(trap, handler, ARRAY_SIZE(args), args, &has_exception);
+  Execution::Call(trap, handler, ARRAY_SIZE(args), args, &has_exception);
   if (has_exception) return Failure::Exception();
 
   return *value;
 }
 
 
 MUST_USE_RESULT MaybeObject* JSProxy::DeletePropertyWithHandler(
     String* name_raw, DeleteMode mode) {
   Isolate* isolate = GetIsolate();
   HandleScope scope(isolate);
@@ skipping 9517 matching lines @@
   if (break_point_objects()->IsUndefined()) return 0;
   // Single beak point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 #endif
 
 
 } }  // namespace v8::internal