Enhance ClassNode prettyprint

lib/compiler/implementation/tree/prettyprint.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.
 
 /**
  * Pretty-prints Node tree in XML-like format.
  *
  * TODO(smok): Add main() to run from command-line to print out tree for given
  * .dart file.
  */
@@ skipping 109 matching lines @@
 
   visitCaseMatch(CaseMatch node) {
     visitNodeWithChildren(node, "CaseMatch");
   }
 
   visitCatchBlock(CatchBlock node) {
     visitNodeWithChildren(node, "CatchBlock");
   }
 
   visitClassNode(ClassNode node) {
-    visitNodeWithChildren(node, "ClassNode");
+    openNode("ClassNode", {
+      "beginToken" : tokenToStringOrNull(node.getBeginToken()),
+      "endToken" : tokenToStringOrNull(node.getEndToken()),
+      "extendsKeyword" : tokenToStringOrNull(node.extendsKeyword),
+    });
+    visitWithPrefix(node.name, "name:");
+    visitWithPrefix(node.superclass, "superclass:");
+    visitWithPrefix(node.interfaces, "interfaces:");
+    visitWithPrefix(node.typeParameters, "typeParameters:");
+    visitWithPrefix(node.defaultClause, "defaultClause:");
+    closeNode("ClassNode");
   }
 
   visitConditional(Conditional node) {
     visitNodeWithChildren(node, "Conditional");
   }
 
   visitContinueStatement(ContinueStatement node) {
     visitNodeWithChildren(node, "ContinueStatement");
   }
 
@@ skipping 229 matching lines @@
     visitWithPrefix(node.type, "type:");
     visitWithPrefix(node.modifiers, "modifiers:");
     visitWithPrefix(node.definitions, "definitions:");
     closeNode("VariableDefinitions");
   }
 
   visitWhile(While node) {
     visitNodeWithChildren(node, "While");
   }
 }