Remove HFixedArrayBaseLength instruction and replace with regular HLoadNamedField.

src/code-stubs-hydrogen.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 492 matching lines @@
 
   if_builder.IfCompare(array_length, graph()->GetConstant0(), Token::EQ);
   if_builder.Then();
 
   // Nothing to do, just change the map.
 
   if_builder.Else();
 
   HInstruction* elements = AddLoadElements(js_array);
 
-  HInstruction* elements_length =
-      AddInstruction(new(zone) HFixedArrayBaseLength(elements));
+  HInstruction* elements_length = AddLoadFixedArrayLength(elements);
 
   HValue* new_elements = BuildAllocateElementsAndInitializeElementsHeader(
       context(), to_kind, elements_length);
 
   BuildCopyElements(context(), elements,
                     casted_stub()->from_kind(), new_elements,
                     to_kind, array_length, elements_length);
 
   AddStore(js_array, HObjectAccess::ForElementsPointer(), new_elements);
 
@@ skipping 252 matching lines @@
   return graph()->GetConstant0();
 }
 
 
 Handle<Code> ToBooleanStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 } }  // namespace v8::internal