Support deserialized compilation of the empty program.

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 '../common.dart';
 import '../common/resolution.dart';
 import '../constants/expressions.dart';
 import '../dart_types.dart';
@@ skipping 90 matching lines @@
     }
   }
 
   /// Serialize [ResolvedAst] that is defined in terms of an AST together with
   /// [TreeElements].
   void serializeParsed() {
     objectEncoder.setUri(
         Key.URI,
         elements.analyzedElement.compilationUnit.script.resourceUri,
         elements.analyzedElement.compilationUnit.script.resourceUri);
+    if (resolvedAst.body != null) {
+      objectEncoder.setInt(Key.BODY, nodeIndices[resolvedAst.body]);
+    }
     AstKind kind;
     if (element.enclosingClass is EnumClassElement) {
       if (element.name == 'index') {
         kind = AstKind.ENUM_INDEX_FIELD;
       } else if (element.name == 'values') {
         kind = AstKind.ENUM_VALUES_FIELD;
       } else if (element.name == 'toString') {
         kind = AstKind.ENUM_TO_STRING;
       } else if (element.isConstructor) {
         kind = AstKind.ENUM_CONSTRUCTOR;
@@ skipping 351 matching lines @@
           });
       }
     }
 
     AstKind kind = objectDecoder.getEnum(Key.SUB_KIND, AstKind.values);
     Node root = computeNode(kind);
     TreeElementMapping elements = new TreeElementMapping(element);
     AstIndexComputer indexComputer = new AstIndexComputer();
     Map<Node, int> nodeIndices = indexComputer.nodeIndices;
     List<Node> nodeList = indexComputer.nodeList;
+    Node body;
+    int bodyNodeIndex = objectDecoder.getInt(Key.BODY, isOptional: true);
+    if (bodyNodeIndex != null) {
+      body = nodeList[bodyNodeIndex];
+    }
     root.accept(indexComputer);
 
     List<JumpTarget> jumpTargets = <JumpTarget>[];
     Map<JumpTarget, List<int>> jumpTargetLabels = <JumpTarget, List<int>>{};
     List<LabelDefinition> labelDefinitions = <LabelDefinition>[];
 
     ListDecoder jumpTargetsDecoder =
         objectDecoder.getList(Key.JUMP_TARGETS, isOptional: true);
     if (jumpTargetsDecoder != null) {
       for (int i = 0; i < jumpTargetsDecoder.length; i++) {
@@ skipping 95 matching lines @@
         if (labelDefinitionId != null) {
           elements.defineLabel(node, labelDefinitions[labelDefinitionId]);
         }
         int targetLabelId =
             objectDecoder.getInt(Key.TARGET_LABEL, isOptional: true);
         if (targetLabelId != null) {
           elements.registerTargetLabel(node, labelDefinitions[targetLabelId]);
         }
       }
     }
-    return new ParsedResolvedAst(element, root, elements);
+    return new ParsedResolvedAst(element, root, body, elements);
   }
 }