Use patching for dart:io.

lib/_internal/libraries.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.
 
 #library('libraries');
 
 /**
  * A bit flag used by [LibraryInfo] indicating that a library is used by dart2js
  */
 const int DART2JS_PLATFORM = 1;
@@ skipping 26 matching lines @@
 
   "crypto": const LibraryInfo(
       "crypto/crypto.dart"),
 
   "html": const LibraryInfo(
       "html/dartium/html_dartium.dart",
       category: "Client",
       dart2jsPath: "html/dart2js/html_dart2js.dart"),
 
   "io": const LibraryInfo(
-      "io/io_runtime.dart",
+      "io/io.dart",
       category: "Server",
-      dart2jsPath: "compiler/implementation/lib/io.dart"),
+      dart2jsPatchPath: "compiler/implementation/lib/io_patch.dart"),
 
   "isolate": const LibraryInfo(
       "isolate/isolate.dart",
       dart2jsPatchPath: "compiler/implementation/lib/isolate_patch.dart"),
 
   "json": const LibraryInfo(
       "json/json.dart"),
 
   "math": const LibraryInfo(
       "math/math.dart",
@@ skipping 88 matching lines @@
                     this.category: "Shared",
                     this.dart2jsPath,
                     this.dart2jsPatchPath,
                     this.implementation: false,
                     this.documented: true,
                     this.platforms: DART2JS_PLATFORM | VM_PLATFORM});
 
   bool get isDart2jsLibrary => (platforms & DART2JS_PLATFORM) != 0;
   bool get isVmLibrary => (platforms & VM_PLATFORM) != 0;
 }