Revert "First step for modular output in fasta."

pkg/front_end/testcases/shaker/transitive_mixins.dart

Index: pkg/front_end/testcases/shaker/transitive_mixins.dart
diff --git a/pkg/front_end/testcases/shaker/transitive_mixins.dart b/pkg/front_end/testcases/shaker/transitive_mixins.dart
deleted file mode 100644
index 461293decb0ad66e428b10f9b3fd144eae962d4f..0000000000000000000000000000000000000000
--- a/pkg/front_end/testcases/shaker/transitive_mixins.dart
+++ /dev/null
@@ -1,8 +0,0 @@
-// Copyright (c) 2017, 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.md file.
-
-import 'lib/lib.dart';
-
-/// We pull in transitive super types from mixins and interfaces.
-foo(M1 x) => null;