Add support for ie11 in our testing scripts

tools/testing/dart/test_suite.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.
 
 /**
  * Classes and methods for enumerating and preparing tests.
  *
  * This library includes:
  *
  * - Creating tests by listing all the Dart files in certain directories,
@@ skipping 2025 matching lines @@
     }
     return args;
   }
 
   static bool isBrowserRuntime(String runtime) {
     const BROWSERS = const [
       'drt',
       'dartium',
       'ie9',
       'ie10',
+      'ie11',      
       'safari',
       'opera',
       'chrome',
       'ff',
       'chromeOnAndroid',
       'ContentShellOnAndroid',
       'DartiumOnAndroid'
     ];
     return BROWSERS.contains(runtime);
   }
@@ skipping 138 matching lines @@
  * $pass tests are expected to pass
  * $failOk tests are expected to fail that we won't fix
  * $fail tests are expected to fail that we should fix
  * $crash tests are expected to crash that we should fix
  * $timeout tests are allowed to timeout
  * $compileErrorSkip tests are skipped on browsers due to compile-time error
 """;
     print(report);
    }
 }