Add support for Element.docRange to the summary.

pkg/analyzer/tool/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 is not
  * executed directly; instead it is parsed and transformed into code that
  * implements the summary format.
  *
  * The code generation process introduces the following non-typical semantics:
@@ skipping 286 matching lines @@
  * Unlinked summary information about a documentation comment.
  */
 class UnlinkedDocumentationComment {
   /**
    * Text of the documentation comment, with '\r\n' replaced by '\n'.
    *
    * References appearing within the doc comment in square brackets are not
    * specially encoded.
    */
   String text;
+
+  /**
+   * Offset of the beginning of the documentation comment relative to the
+   * beginning of the file.
+   */
+  int offset;
+
+  /**
+   * Length of the documentation comment (prior to replacing '\r\n' with '\n').
+   */
+  int length;
 }
 
 /**
  * Unlinked summary information about an enum declaration.
  */
 class UnlinkedEnum {
   /**
    * Name of the enum type.
    */
   String name;
@@ skipping 661 matching lines @@
   /**
    * Indicates whether the variable is declared using the `const` keyword.
    */
   bool isConst;
 
   /**
    * Indicates whether this variable lacks an explicit type declaration.
    */
   bool hasImplicitType;
 }