Add summary support for ParameterElement.defaultValueCode.

pkg/analyzer/lib/src/summary/idl.dart

 // Copyright (c) 2015, 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.
 
 /**
  * This file is an "idl" style description of the summary format.  It
  * contains abstract classes which declare the interface for reading data from
  * summaries.  It is parsed and transformed into code that implements the
  * summary format.
  *
@@ skipping 1464 matching lines @@
   String get name;
 
   /**
    * Offset of the parameter name relative to the beginning of the file.
    */
   @informative
   @Id(1)
   int get nameOffset;
 
   /**
+   * If the parameter has a default value, the source text of the constant
+   * expression in the default value.  Otherwise the empty string.
+   */
+  @informative
+  @Id(13)
+  String get defaultValueCode;
+
+  /**
    * If [isFunctionTyped] is `true`, the parameters of the function type.
    */
   @Id(8)
   List<UnlinkedParam> get parameters;
 
   /**
    * If [isFunctionTyped] is `true`, the declared return type.  If
    * [isFunctionTyped] is `false`, the declared type.  Absent if the type is
    * implicit.
    */
@@ skipping 449 matching lines @@
    */
   @Id(11)
   int get visibleLength;
 
   /**
    * If a local variable, the beginning of the visible range; zero otherwise.
    */
   @Id(12)
   int get visibleOffset;
 }