cleanup patch generation to preseve comments and remove @patch

test/generated_sdk/lib/core/uri.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.
 
 part of dart.core;
 
 /**
  * A parsed URI, such as a URL.
  *
  * **See also:**
@@ skipping 680 matching lines @@
    * new Uri.file(r"\\server\share\file", windows: true);
    * ```
    *
    * If the path passed is not a legal file path [ArgumentError] is thrown.
    */
   factory Uri.file(String path, {bool windows}) {
     windows = windows == null ? Uri._isWindows : windows;
     return windows ? _makeWindowsFileUrl(path) : _makeFileUri(path);
   }
 
-  @patch
+  /**
+   * Returns the natural base URI for the current platform.
+   *
+   * When running in a browser this is the current URL (from
+   * `window.location.href`).
+   *
+   * When not running in a browser this is the file URI referencing
+   * the current working directory.
+   */
   static Uri get base {
     String uri = Primitives.currentUri();
     if (uri != null) return Uri.parse(uri);
     throw new UnsupportedError("'Uri.base' is not supported");
   }
 
-  @patch
   static bool get _isWindows => false;
 
   static _checkNonWindowsPathReservedCharacters(List<String> segments,
                                                 bool argumentError) {
     segments.forEach((segment) {
       if (segment.contains("/")) {
         if (argumentError) {
           throw new ArgumentError("Illegal path character $segment");
         } else {
           throw new UnsupportedError("Illegal path character $segment");
@@ skipping 1676 matching lines @@
       0xafff,   // 0x30 - 0x3f  1111111111110101
                 //              @ABCDEFGHIJKLMNO
       0xffff,   // 0x40 - 0x4f  1111111111111111
                 //              PQRSTUVWXYZ    _
       0x87ff,   // 0x50 - 0x5f  1111111111100001
                 //               abcdefghijklmno
       0xfffe,   // 0x60 - 0x6f  0111111111111111
                 //              pqrstuvwxyz   ~
       0x47ff];  // 0x70 - 0x7f  1111111111100010
 }