Refactoring to prepare for kernel based jump targets

pkg/compiler/lib/src/serialization/resolved_ast_serialization.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.
 
 library dart2js.serialization.resolved_ast;
 
 import 'package:front_end/src/fasta/parser.dart' show Parser, ParserError;
 import 'package:front_end/src/fasta/scanner.dart';
 
 import '../common.dart';
@@ skipping 562 matching lines @@
 
     ListDecoder jumpTargetsDecoder =
         objectDecoder.getList(Key.JUMP_TARGETS, isOptional: true);
     if (jumpTargetsDecoder != null) {
       for (int i = 0; i < jumpTargetsDecoder.length; i++) {
         ObjectDecoder decoder = jumpTargetsDecoder.getObject(i);
         ExecutableElement executableContext =
             decoder.getElement(Key.EXECUTABLE_CONTEXT);
         Node statement = nodeList[decoder.getInt(Key.NODE)];
         int nestingLevel = decoder.getInt(Key.NESTING_LEVEL);
-        JumpTarget jumpTarget =
+        JumpTargetX jumpTarget =
             new JumpTargetX(statement, nestingLevel, executableContext);
         jumpTarget.isBreakTarget = decoder.getBool(Key.IS_BREAK_TARGET);
         jumpTarget.isContinueTarget = decoder.getBool(Key.IS_CONTINUE_TARGET);
         jumpTargetLabels[jumpTarget] =
             decoder.getInts(Key.LABELS, isOptional: true);
         jumpTargets.add(jumpTarget);
       }
     }
 
     ListDecoder labelDefinitionsDecoder =
@@ skipping 115 matching lines @@
         }
       }
     }
     element.resolvedAst =
         new ParsedResolvedAst(element, root, body, elements, uri);
   }
 }
 
 const Key PARAMETER_NODE = const Key('parameter.node');
 const Key PARAMETER_INITIALIZER = const Key('parameter.initializer');