Accept more labels per switch case.

frog/tests/leg_only/switch_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.
 
 switcher(val) {
   var x = 0;
   switch (val) {
   case 1:
     x = 100;
     break;
   case 2:
     x = 200;
     break;
   case 3:
     x = 300;
     break;
   default:
     return 400;
     break; // Intentional dead code (regression test for crash).
   }
   return x;
 }
 
+
+// Check unambiguated grammar allowing multiple lables per case/default.
+switcher2(val) {
+  var x = 0;
+  switch (val) {
+    foo:
+    bar:
+    case 1:
+    baz:
+    case 2:
+      fez: {
+        x = 100;
+        break fez;
+      }
+      break;
+    hest:
+    fisk:
+    case 3:
+    case 4:
+    svin:
+    default:
+      barber: {
+        if (val > 2) {
+          x = 200;
+          break;
+        } else {
+          // Enable when continue to switch-case is implemented.
+          continue hest;  /// 03: compile-time error
+        }
+      }
+  }
+  return x;
+}
+
+
+badswitches(val) {
+  // Test some badly formed switch bodies.
+  // 01 - a label/statement without a following case/default.
+  // 02 - a label without a following case/default or statement.
+  switch (val) {
+    foo: break;     /// 01: compile-time error
+    case 2:         /// 02: compile-time error
+    foo:            /// 02: continued
+  }
+}
+
 main() {
   Expect.equals(100, switcher(1));
   Expect.equals(200, switcher(2));
   Expect.equals(300, switcher(3));
   Expect.equals(400, switcher(4));
+
+  Expect.equals(100, switcher2(1));
+  Expect.equals(100, switcher2(2));
+  Expect.equals(200, switcher2(3));
+  Expect.equals(200, switcher2(4));
+  Expect.equals(200, switcher2(5));
+
+  badswitches(42);
 }