Expand part declarations in the builtin library python scripts to avoid having to repeat part decla…

runtime/bin/io.dart

Index: runtime/bin/io.dart
diff --git a/runtime/bin/io.dart b/runtime/bin/io.dart
index 9faff4eef9dbe18555017a3fc0b300b71b5cc66f..ddc6ca5875f165566cd076ace2c370784aa5591a 100644
--- a/runtime/bin/io.dart
+++ b/runtime/bin/io.dart
@@ -2,17 +2,4 @@
 // 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.
 
-// We should be able to get rid of this file. This is used to set up
-// the dart:io library for the VM because it cannot use the actual library
-// file which is in lib/io/io.dart.
-
-#library("dart:io");
-#import("dart:async");
-#import("dart:collection");
-#import("dart:crypto");
-#import("dart:isolate");
-#import("dart:math");
-#import("dart:nativewrappers");
-#import("dart:scalarlist");
-#import("dart:uri");
-#import("dart:utf");
+import 'dart:nativewrappers';