Address Siva's review comment

tests/language/throw_expr_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.
 
 // Dart test program for testing throw expressions.
 
 void test1() {
   var x = 6;
   try {
     throw x = 10;
@@ skipping 32 matching lines @@
 
 bar(x, y) => throw "foo" "${throw x}";
 
 class Q {
   var qqq;
   f(x) { qqq = x; }
 }
 
 void test3() {
   try {
-    throw throw throw "throw";
+    throw throw throw "up";
   } catch(e) {
-    Expect.equals("throw", e);
+    Expect.equals("up", e);
   }
 
   var x = 10;
   try {
     foo(x = 12, throw 7);
   } catch(e) {
     Expect.equals(7, e);
     Expect.equals(12, x);
   }
 
@@ skipping 21 matching lines @@
     Expect.equals(77, e);
     Expect.equals(11, x.qqq);
   }
 }
 
 main() {
   test1();
   test2();
   test3();
 }