Handle labelled continue statements

pkg/compiler/lib/src/ssa/jump_handler.dart

 // Copyright (c) 2016, 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 '../common.dart';
 import '../elements/jumps.dart';
 import '../tree/tree.dart' as ast;
 
 import 'graph_builder.dart';
 import 'locals_handler.dart';
@@ skipping 81 matching lines @@
   }
 
   void generateContinue([LabelDefinition label]) {
     HInstruction continueInstruction;
     if (label == null) {
       continueInstruction = new HContinue(target);
     } else {
       continueInstruction = new HContinue.toLabel(label);
       // Switch case continue statements must be handled by the
       // [SwitchCaseJumpHandler].
-      assert(label.target.statement is! ast.SwitchCase);
+      assert(!label.target.isSwitchCase);
     }
     LocalsHandler locals = new LocalsHandler.from(builder.localsHandler);
     builder.close(continueInstruction);
     jumps.add(new _JumpHandlerEntry(continueInstruction, locals));
   }
 
   void forEachBreak(Function action) {
     for (_JumpHandlerEntry entry in jumps) {
       if (entry.isBreak()) action(entry.jumpInstruction, entry.locals);
     }
@@ skipping 118 matching lines @@
             targetIndexMap[continueTarget] = switchIndex;
             assert(builder.jumpTargets[continueTarget] == null);
             builder.jumpTargets[continueTarget] = this;
           }
         }
       }
       switchIndex++;
     }
   }
 }