Removed Instructions object from Observatory models

runtime/observatory/tests/observatory_ui/mocks/objects/instructions.dart

Index: runtime/observatory/tests/observatory_ui/mocks/objects/instructions.dart
diff --git a/runtime/observatory/tests/observatory_ui/mocks/objects/instructions.dart b/runtime/observatory/tests/observatory_ui/mocks/objects/instructions.dart
deleted file mode 100644
index f50b011da8e939ed6b5785a89d619fff786c9acc..0000000000000000000000000000000000000000
--- a/runtime/observatory/tests/observatory_ui/mocks/objects/instructions.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.
-
-part of mocks;
-
-class InstructionsRefMock implements M.InstructionsRef {
-  final String id;
-  final M.CodeRef code;
-  const InstructionsRefMock({this.id: 'instructions-id',
-                             this.code: const CodeRefMock(
-                                        name: 'instruction-ref-code-ref')});
-}