Create ast/ and parsing/ subdirectories and move appropriate files

src/parsing/scanner-character-streams.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_SCANNER_CHARACTER_STREAMS_H_
-#define V8_SCANNER_CHARACTER_STREAMS_H_
+#ifndef V8_PARSING_SCANNER_CHARACTER_STREAMS_H_
+#define V8_PARSING_SCANNER_CHARACTER_STREAMS_H_
 
 #include "src/handles.h"
-#include "src/scanner.h"
+#include "src/parsing/scanner.h"
 #include "src/vector.h"
 
 namespace v8 {
 namespace internal {
 
 // Forward declarations.
 class ExternalTwoByteString;
 
 // A buffered character stream based on a random access character
 // source (ReadBlock can be called with pos_ pointing to any position,
@@ skipping 159 matching lines @@
 
  private:
   static const size_t kNoBookmark = -1;
 
   size_t bookmark_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_SCANNER_CHARACTER_STREAMS_H_
+#endif  // V8_PARSING_SCANNER_CHARACTER_STREAMS_H_