Add regression test for issue 20476

tests/language/issue20476_test.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.
-//
 
-import 'dart:profiler';
 import 'package:expect/expect.dart';
 
-testGaugeDouble() {
-  Expect.throws(() {
-    // max argument is not a double
-    gauge = new Gauge('test', 'alpha bravo', 1.0, 4);
-  });
+foo() {
+  try {
+    try {
+      return 1;
+    } catch (e1) {
+    } finally {
+      return 3;
+    }
+  } catch (e2) {
+  } finally  {
+    return 5;
+  }
 }
 
+
 main() {
-  testGaugeDouble();
+  Expect.equals(5, foo());
 }