Fix typo in analyzer error message.

pkg/analyzer/lib/src/generated/error.dart

 // Copyright (c) 2014, 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.
 
 library engine.error;
 
 import 'dart:collection';
 
 import 'ast.dart' show AstNode;
 import 'element.dart';
@@ skipping 499 matching lines @@
   static const CompileTimeErrorCode AWAIT_IN_WRONG_CONTEXT =
       const CompileTimeErrorCode('AWAIT_IN_WRONG_CONTEXT',
           "The await expression can only be used in a function marked as async or async*");
 
   /**
    * 12.30 Identifier Reference: It is a compile-time error to use a built-in
    * identifier other than dynamic as a type annotation.
    */
   static const CompileTimeErrorCode BUILT_IN_IDENTIFIER_AS_TYPE =
       const CompileTimeErrorCode('BUILT_IN_IDENTIFIER_AS_TYPE',
-          "The built-in identifier '{0}' cannot be as a type");
+          "The built-in identifier '{0}' cannot be used as a type");
 
   /**
    * 12.30 Identifier Reference: It is a compile-time error if a built-in
    * identifier is used as the declared name of a class, type parameter or type
    * alias.
    */
   static const CompileTimeErrorCode BUILT_IN_IDENTIFIER_AS_TYPE_NAME =
       const CompileTimeErrorCode('BUILT_IN_IDENTIFIER_AS_TYPE_NAME',
           "The built-in identifier '{0}' cannot be used as a type name");
 
@@ skipping 4399 matching lines @@
    * Initialize a newly created error code to have the given [name].
    */
   const TodoCode(String name) : super(name, "{0}");
 
   @override
   ErrorSeverity get errorSeverity => ErrorSeverity.INFO;
 
   @override
   ErrorType get type => ErrorType.TODO;
 }