Revert hiding of VM-only coreimpl list implementation types. While I

lib/compiler/implementation/lib/io.dart

Index: lib/compiler/implementation/lib/io.dart
diff --git a/lib/compiler/implementation/lib/io.dart b/lib/compiler/implementation/lib/io.dart
index 6fbcda0e627d089e0bcc8d55772057166f7f9de6..a45be35c9dadea06af9a8616a3a0f6a98c6d72f5 100644
--- a/lib/compiler/implementation/lib/io.dart
+++ b/lib/compiler/implementation/lib/io.dart
@@ -27,8 +27,7 @@
 #import("dart:crypto");
 #import("dart:utf");
 #source('../../../../runtime/bin/buffer_list.dart');
-// Uses native keyword.
-//#source('../../../../runtime/bin/common.dart');
+#source('../../../../runtime/bin/common.dart');
 #source('../../../../runtime/bin/chunked_stream.dart');
 #source('../../../../runtime/bin/directory.dart');
 // Uses native keyword.
@@ -67,39 +66,6 @@
 #source('../../../../runtime/bin/websocket.dart');
 #source('../../../../runtime/bin/websocket_impl.dart');
 
-/**
-  * An [OSError] object holds information about an error from the
-  * operating system.
-  */
-class OSError {
-  /** Constant used to indicate that no OS error code is available. */
-  static const int noErrorCode = -1;
-
-  /** Creates an OSError object from a message and an errorCode. */
-  const OSError([String this.message = "", int this.errorCode = noErrorCode]);
-
-  /** Converts an OSError object to a string representation. */
-  String toString() {
-    throw UnsupportedOperationException('OSError.toString');
-  }
-
-  /**
-    * Error message supplied by the operating system. null if no message is
-    * associated with the error.
-    */
-  final String message;
-
-  /**
-    * Error code supplied by the operating system. Will have the value
-    * [noErrorCode] if there is no error code associated with the error.
-    */
-  final int errorCode;
-}
-
-List _ensureFastAndSerializableBuffer(List buffer, int offset, int bytes) {
-  throw new UnsupportedOperationException('_ensureFastAndSerializableBuffer');
-}
-
 class _File {
   factory File(arg) {
     throw new UnsupportedOperationException('new File($arg)');