Move kernel baseline tests to front_end.

pkg/front_end/test/fasta/rasta/mixin_library.dart

Index: pkg/front_end/test/fasta/rasta/mixin_library.dart
diff --git a/pkg/front_end/test/fasta/rasta/mixin_library.dart b/pkg/front_end/test/fasta/rasta/mixin_library.dart
deleted file mode 100644
index 43608356061f332ea5d3b80a2f65f8c6282791a1..0000000000000000000000000000000000000000
--- a/pkg/front_end/test/fasta/rasta/mixin_library.dart
+++ /dev/null
@@ -1,24 +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.md file.
-
-library test.mixin_library;
-
-f() => 2;
-
-V() => 87;
-
-_private() => 117;
-
-class Mixin<T> {
-  var x = f(), y, z;
-  T t;
-  foo() => super.foo() + f();
-  T g(T a) => null;
-  h() => V();
-  l() => _private();
-  _privateMethod() => 49;
-  publicMethod() => _privateMethod();
-}
-
-foo(m) => m._privateMethod();