Move kernel baseline tests to front_end.

pkg/front_end/testcases/rasta/class_member.dart

 // 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.
 
 // Tests that class members are listed in the normal order.
 
 class Foo {
   a() {}
   b() {}
   c() {}
   var field1;
   var field2;
   var field3;
   Foo.constructor1();
   Foo.constructor2();
   Foo.constructor3();
 }