Separate DuplicateFinder from Scanner.

src/parsing/preparser.cc

 // Copyright 2011 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 <cmath>
 
 #include "src/allocation.h"
 #include "src/base/logging.h"
 #include "src/conversions-inl.h"
 #include "src/conversions.h"
 #include "src/globals.h"
 #include "src/list.h"
+#include "src/parsing/duplicate-finder.h"
 #include "src/parsing/parser-base.h"
 #include "src/parsing/preparse-data-format.h"
 #include "src/parsing/preparse-data.h"
 #include "src/parsing/preparser.h"
 #include "src/unicode.h"
 #include "src/utils.h"
 
 namespace v8 {
 namespace internal {
 
@@ skipping 1241 matching lines @@
 
   body->Add(PreParserStatement::ExpressionStatement(return_value), zone());
 }
 
 #undef CHECK_OK
 #undef CHECK_OK_CUSTOM
 
 
 }  // namespace internal
 }  // namespace v8