Remove unused TokenType.IS.

pkg/dev_compiler/lib/src/compiler/ast_builder.dart

 // Copyright (c) 2015, 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.
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_ast_factory.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/src/dart/ast/token.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:logging/logging.dart' as logger;
@@ skipping 149 matching lines @@
       case ">>":
         return TokenType.GT_GT;
       case ">>=":
         return TokenType.GT_GT_EQ;
       case "#":
         return TokenType.HASH;
       case "[]":
         return TokenType.INDEX;
       case "[]=":
         return TokenType.INDEX_EQ;
-      case "is":
-        return TokenType.IS;
       case "<":
         return TokenType.LT;
       case "<=":
         return TokenType.LT_EQ;
       case "<<":
         return TokenType.LT_LT;
       case "<<=":
         return TokenType.LT_LT_EQ;
       case "-":
         return TokenType.MINUS;
@@ skipping 413 matching lines @@
     Label l = astFactory.label(s, new Token(TokenType.COLON, 0));
     return astFactory.namedExpression(l, e);
   }
 
   static VariableDeclarationStatement variableDeclarationStatement(
       VariableDeclarationList varDecl) {
     var semi = new Token(TokenType.SEMICOLON, 0);
     return astFactory.variableDeclarationStatement(varDecl, semi);
   }
 }