Remove unnecessary AST node for ++ and -- operations.

src/parser.cc

 // Copyright 2010 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 2575 matching lines @@
           isolate()->factory()->invalid_lhs_in_prefix_op_symbol();
       expression = NewThrowReferenceError(type);
     }
 
     if (top_scope_->is_strict_mode()) {
       // Prefix expression operand in strict mode may not be eval or arguments.
       CheckStrictModeLValue(expression, "strict_lhs_prefix", CHECK_OK);
     }
 
     int position = scanner().location().beg_pos;
-    IncrementOperation* increment =
-        new(zone()) IncrementOperation(op, expression);
-    return new(zone()) CountOperation(true /* prefix */, increment, position);
+    return new(zone()) CountOperation(op,
+                                      true /* prefix */,
+                                      expression,
+                                      position);
 
   } else {
     return ParsePostfixExpression(ok);
   }
 }
 
 
 Expression* Parser::ParsePostfixExpression(bool* ok) {
   // PostfixExpression ::
   //   LeftHandSideExpression ('++' | '--')?
@@ skipping 11 matching lines @@
       expression = NewThrowReferenceError(type);
     }
 
     if (top_scope_->is_strict_mode()) {
       // Postfix expression operand in strict mode may not be eval or arguments.
       CheckStrictModeLValue(expression, "strict_lhs_prefix", CHECK_OK);
     }
 
     Token::Value next = Next();
     int position = scanner().location().beg_pos;
-    IncrementOperation* increment =
-        new(zone()) IncrementOperation(next, expression);
     expression =
-        new(zone()) CountOperation(false /* postfix */, increment, position);
+        new(zone()) CountOperation(next,
+                                   false /* postfix */,
+                                   expression,
+                                   position);
   }
   return expression;
 }
 
 
 Expression* Parser::ParseLeftHandSideExpression(bool* ok) {
   // LeftHandSideExpression ::
   //   (NewExpression | MemberExpression) ...
 
   Expression* result;
@@ skipping 2515 matching lines @@
                                    info->is_global(),
                                    info->StrictMode());
     }
   }
 
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal