Re-land beginning Dart 2.0 test migration.

tests/language_2/aborting_switch_case_test.dart

 // Copyright (c) 2013, 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.
 
 // Regression test for dart2js that used to be confused when inlining
 // method that always aborts in a switch case.
 
 import "package:expect/expect.dart";
 
 foo() {
   throw 42;
 }
 
 main() {
   var exception;
   try {
     switch (42) {
       case 42:
         foo();
         foo();
         break;
     }
   } catch (e) {
     exception = e;
   }
   Expect.equals(42, exception);
 }