Fix build break in dartdoc.

utils/dartdoc/dartdoc.dart

 // Copyright (c) 2011, 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.
 
 /**
  * To use it, from this directory, run:
  *
  *     $ ./dartdoc <path to .dart file>
  *
  * This will create a "docs" directory with the docs for your libraries. To
@@ skipping 887 matching lines @@
     return const RegExp(@'^\w+:').hasMatch(url);
   }
 
   /** Gets the URL to the documentation for [library]. */
   String libraryUrl(Library library) {
     return '${sanitize(library.name)}.html';
   }
 
   /** Gets the URL for the documentation for [type]. */
   String typeUrl(Type type) {
+    if (type.isTop) return '${sanitize(type.library.name)}.html';
     // Always get the generic type to strip off any type parameters or
     // arguments. If the type isn't generic, genericType returns `this`, so it
     // works for non-generic types too.
     return '${sanitize(type.library.name)}/${type.genericType.name}.html';
   }
 
   /** Gets the URL for the documentation for [member]. */
   String memberUrl(Member member) {
-    return '${typeUrl(member.declaringType)}#${member.name}';
+    final typeUrl = typeUrl(member.declaringType);
+    if (!member.isConstructor) return '$typeUrl#${member.name}';
+    if (member.constructorName == '') return '$typeUrl#new:${member.name}';
+    return '$typeUrl#new:${member.name}.${member.constructorName}';
   }
 
   /** Gets the anchor id for the document for [member]. */
   String memberAnchor(Member member) {
     return '${member.name}';
   }
 
   /**
    * Creates a hyperlink. Handles turning the [href] into an appropriate
    * relative path from the current file.
@@ skipping 226 matching lines @@
 
     return new md.Element.text('code', name);
   }
 
   // TODO(rnystrom): Move into SourceSpan?
   int getSpanColumn(SourceSpan span) {
     final line = span.file.getLine(span.start);
     return span.file.getColumn(line, span.start);
   }
 }