Non-JSArrays must always have holey elements.

src/ast.h

 // 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.
 
 #ifndef V8_AST_H_
 #define V8_AST_H_
 
 #include "src/v8.h"
 
 #include "src/assembler.h"
@@ skipping 1850 matching lines @@
   }
   int AllocationSiteFeedbackSlot() {
     DCHECK(callnew_feedback_slot_ != kInvalidFeedbackSlot);
     DCHECK(FLAG_pretenuring_call_new);
     return callnew_feedback_slot_ + 1;
   }
 
   void RecordTypeFeedback(TypeFeedbackOracle* oracle);
   virtual bool IsMonomorphic() OVERRIDE { return is_monomorphic_; }
   Handle<JSFunction> target() const { return target_; }
-  ElementsKind elements_kind() const { return elements_kind_; }
   Handle<AllocationSite> allocation_site() const {
     return allocation_site_;
   }
 
   static int feedback_slots() { return 1; }
 
   BailoutId ReturnId() const { return return_id_; }
 
  protected:
   CallNew(Zone* zone, Expression* expression, ZoneList<Expression*>* arguments,
           int pos, IdGen* id_gen)
       : Expression(zone, pos, id_gen),
         expression_(expression),
         arguments_(arguments),
         is_monomorphic_(false),
-        elements_kind_(GetInitialFastElementsKind()),
         callnew_feedback_slot_(kInvalidFeedbackSlot),
         return_id_(id_gen->GetNextId()) {}
 
  private:
   Expression* expression_;
   ZoneList<Expression*>* arguments_;
 
   bool is_monomorphic_;
   Handle<JSFunction> target_;
-  ElementsKind elements_kind_;
   Handle<AllocationSite> allocation_site_;
   int callnew_feedback_slot_;
 
   const BailoutId return_id_;
 };
 
 
 // The CallRuntime class does not represent any official JavaScript
 // language construct. Instead it is used to call a C or JS function
 // with a set of arguments. This is used from the builtins that are
@@ skipping 1626 matching lines @@
   Zone* zone_;
   Visitor visitor_;
   AstValueFactory* ast_value_factory_;
   AstNode::IdGen* id_gen_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_