Create ast/ and parsing/ subdirectories and move appropriate files

src/rewriter.h

-// 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.
-
-#ifndef V8_REWRITER_H_
-#define V8_REWRITER_H_
-
-namespace v8 {
-namespace internal {
-
-class AstValueFactory;
-class DoExpression;
-class ParseInfo;
-class Parser;
-
-class Rewriter {
- public:
-  // Rewrite top-level code (ECMA 262 "programs") so as to conservatively
-  // include an assignment of the value of the last statement in the code to
-  // a compiler-generated temporary variable wherever needed.
-  //
-  // Assumes code has been parsed and scopes have been analyzed.  Mutates the
-  // AST, so the AST should not continue to be used in the case of failure.
-  static bool Rewrite(ParseInfo* info);
-
-  // Rewrite a list of statements, using the same rules as a top-level program,
-  // to  ensure identical behaviour of completion result.
-  static bool Rewrite(Parser* parser, DoExpression* expr,
-                      AstValueFactory* factory);
-};
-
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_REWRITER_H_