Merge more Kernel infrastructure from kernel_sdk SDK fork.

runtime/lib/typed_data.dart

Index: runtime/lib/typed_data.dart
diff --git a/runtime/lib/typed_data.dart b/runtime/lib/typed_data.dart
index c010555e2141c7f46b6f506aac571da0b86ae196..0875fbc989e0b46aa7d0f4846c14606407f4ddc1 100644
--- a/runtime/lib/typed_data.dart
+++ b/runtime/lib/typed_data.dart
@@ -2,6 +2,9 @@
 // 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.
 
+// Unlike the other SDK libraries, this file is not a patch that is applied to
+// dart:typed_data.  Instead, it completely replaces the implementation from the
+// SDK.
 library dart.typed_data;
 
 import "dart:_internal";