Handle "is" and "as" like other keywords.

dart/lib/compiler/implementation/scanner/token.dart

 // Copyright (c) 2011, 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.
 
 const int EOF_TOKEN = 0;
 
 const int KEYWORD_TOKEN = $k;
 const int IDENTIFIER_TOKEN = $a;
 const int BAD_INPUT_TOKEN = $X;
 const int DOUBLE_TOKEN = $d;
@@ skipping 53 matching lines @@
 const int STAR_EQ_TOKEN = BAR_EQ_TOKEN + 1;
 const int PLUS_PLUS_TOKEN = STAR_EQ_TOKEN + 1;
 const int PLUS_EQ_TOKEN = PLUS_PLUS_TOKEN + 1;
 const int MINUS_MINUS_TOKEN = PLUS_EQ_TOKEN + 1;
 const int MINUS_EQ_TOKEN = MINUS_MINUS_TOKEN + 1;
 const int TILDE_SLASH_EQ_TOKEN = MINUS_EQ_TOKEN + 1;
 const int TILDE_SLASH_TOKEN = TILDE_SLASH_EQ_TOKEN + 1;
 const int PERCENT_EQ_TOKEN = TILDE_SLASH_TOKEN + 1;
 const int GT_GT_TOKEN = PERCENT_EQ_TOKEN + 1;
 const int CARET_EQ_TOKEN = GT_GT_TOKEN + 1;
-const int IS_TOKEN = CARET_EQ_TOKEN + 1;
-const int AS_TOKEN = IS_TOKEN + 1;
-const int COMMENT_TOKEN = AS_TOKEN + 1;
+const int COMMENT_TOKEN = CARET_EQ_TOKEN + 1;
 const int STRING_INTERPOLATION_IDENTIFIER_TOKEN = COMMENT_TOKEN + 1;
 
 // TODO(ahe): Get rid of this.
 const int UNKNOWN_TOKEN = 1024;
 
 /**
  * A token that doubles as a linked list.
  */
 class Token implements Spannable {
   /**
@@ skipping 314 matching lines @@
   const PrecedenceInfo(const SourceString('==='), 9, EQ_EQ_EQ_TOKEN);
 const PrecedenceInfo EQ_EQ_INFO =
   const PrecedenceInfo(const SourceString('=='), 9, EQ_EQ_TOKEN);
 
 // Relational operators.
 const PrecedenceInfo GT_EQ_INFO =
   const PrecedenceInfo(const SourceString('>='), 10, GT_EQ_TOKEN);
 const PrecedenceInfo GT_INFO =
   const PrecedenceInfo(const SourceString('>'), 10, GT_TOKEN);
 const PrecedenceInfo IS_INFO =
-  const PrecedenceInfo(const SourceString('is'), 10, IS_TOKEN);
+  const PrecedenceInfo(const SourceString('is'), 10, KEYWORD_TOKEN);
 const PrecedenceInfo AS_INFO =
-  const PrecedenceInfo(const SourceString('as'), 10, AS_TOKEN);
+  const PrecedenceInfo(const SourceString('as'), 10, KEYWORD_TOKEN);
 const PrecedenceInfo LT_EQ_INFO =
   const PrecedenceInfo(const SourceString('<='), 10, LT_EQ_TOKEN);
 const PrecedenceInfo LT_INFO =
   const PrecedenceInfo(const SourceString('<'), 10, LT_TOKEN);
 
 // Shift operators.
 const PrecedenceInfo GT_GT_INFO =
   const PrecedenceInfo(const SourceString('>>'), 11, GT_GT_TOKEN);
 const PrecedenceInfo LT_LT_INFO =
   const PrecedenceInfo(const SourceString('<<'), 11, LT_LT_TOKEN);
@@ skipping 71 matching lines @@
 
 const PrecedenceInfo HEXADECIMAL_INFO =
   const PrecedenceInfo(const SourceString('hexadecimal'), 0, HEXADECIMAL_TOKEN);
 
 const PrecedenceInfo COMMENT_INFO =
   const PrecedenceInfo(const SourceString('comment'), 0, COMMENT_TOKEN);
 
 // For reporting lexical errors.
 const PrecedenceInfo ERROR_INFO =
   const PrecedenceInfo(const SourceString('?'), 0, UNKNOWN_TOKEN);