Add 'part of' in dart2js code.

lib/compiler/implementation/scanner/scanner.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+part of scanner;
+
 abstract class Scanner {
   Token tokenize();
 }
 
 /**
  * Common base class for a Dart scanner.
  */
 abstract class AbstractScanner<T extends SourceString> implements Scanner {
   abstract int advance();
   abstract int nextByte();
@@ skipping 234 matching lines @@
 
     if (identical(next, $PERIOD)) {
       return tokenizeDotsOrNumber(next);
     }
 
     if (identical(next, $0)) {
       return tokenizeHexOrNumber(next);
     }
 
     // TODO(ahe): Would a range check be faster?
-    if (identical(next, $1) || identical(next, $2) || identical(next, $3) 
+    if (identical(next, $1) || identical(next, $2) || identical(next, $3)
         || identical(next, $4) ||  identical(next, $5) || identical(next, $6)
         || identical(next, $7) || identical(next, $8) || identical(next, $9)) {
       return tokenizeNumber(next);
     }
 
     if (identical(next, $EOF)) {
       return $EOF;
     }
     if (next < 0x1f) {
       return error(new SourceString("unexpected character $next"));
@@ skipping 594 matching lines @@
       next = advance();
     }
     return error(const SourceString("unterminated string literal"));
   }
 
   int error(SourceString message) {
     appendByteStringToken(BAD_INPUT_INFO, message);
     return advance(); // Ensure progress.
   }
 }