Fix constructors for HLoadNamedField.

src/hydrogen-instructions.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 "v8.h"
 
 #include "double.h"
 #include "factory.h"
 #include "hydrogen-infer-representation.h"
 #include "property-details-inl.h"
@@ skipping 3400 matching lines @@
 
 void HParameter::PrintDataTo(StringStream* stream) {
   stream->Add("%u", index());
 }
 
 
 void HLoadNamedField::PrintDataTo(StringStream* stream) {
   object()->PrintNameTo(stream);
   access_.PrintTo(stream);
 
-  if (maps()->size() != 0) {
+  if (maps() != NULL) {
     stream->Add(" [%p", *maps()->at(0).handle());
     for (int i = 1; i < maps()->size(); ++i) {
       stream->Add(",%p", *maps()->at(i).handle());
     }
     stream->Add("]");
   }
 
   if (HasDependency()) {
     stream->Add(" ");
     dependency()->PrintNameTo(stream);
@@ skipping 1344 matching lines @@
       break;
     case kExternalMemory:
       stream->Add("[external-memory]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal