Revert "Merge more Kernel infrastructure from kernel_sdk SDK fork."

runtime/bin/nativewrappers.dart

Index: runtime/bin/nativewrappers.dart
diff --git a/runtime/bin/nativewrappers.dart b/runtime/bin/nativewrappers.dart
deleted file mode 100644
index 7ed73b94d3ca022a98313c5f403adeffc317594d..0000000000000000000000000000000000000000
--- a/runtime/bin/nativewrappers.dart
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright (c) 2016, 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.
-
-// This library is only used by the Kernel frontend.
-// VM creates these classes in Library::InitNativeWrappersLibrary.
-
-library dart.nativewrappers;
-
-class NativeFieldWrapperClass1 extends Object {}
-class NativeFieldWrapperClass2 extends Object {}
-class NativeFieldWrapperClass3 extends Object {}
-class NativeFieldWrapperClass4 extends Object {}