Change the field and constructor parameter types of NoSuchMethodError to Symbol.

tests/language/call_nonexistent_static_test.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.
 
 import "package:expect/expect.dart";
 
 // When attempting to call a nonexistent static method, getter or setter, check
 // that a NoSuchMethodError is thrown.
 
 class C {}
 
 class D {
   get hest => 1;  /// 04: continued
   set hest(val) {}  /// 05: continued
 }
 
 get fisk => 2; /// 09: continued
 set fisk(val) {} /// 10: continued
 
 expectNsme([void fun()]) {
   if (fun != null) {
     Expect.throws(fun, (e) => e is NoSuchMethodError);
   }
 }
 
 alwaysThrows() {
-  throw new NoSuchMethodError(null, 'foo', [], {});
+  throw new NoSuchMethodError(null, const Symbol('foo'), [], {});
 }
 
 test01() {
   C.hest = 1;  /// 01: static type warning
 }
 
 test02() {
   C.hest;  /// 02: static type warning
 }
 
@@ skipping 55 matching lines @@
   expectNsme(
     test08  /// 08: continued
   );
   expectNsme(
     test09  /// 09: continued
   );
   expectNsme(
     test10  /// 10: continued
   );
 }