Move kernel baseline tests to front_end.

pkg/front_end/test/fasta/accessors.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 file.
-
-void set onlySetter(value) {
-  print("onlySetter called with $value.");
-}
-
-class C {
-  void set onlySetter(value) {
-    print("C.onlySetter called with $value.");
-  }
-
-  testC() {
-    try {
-      print(onlySetter);
-      throw "No error thrown";
-    } on NoSuchMethodError catch (e) {
-      print("Expected error: $e");
-    }
-    onlySetter = "hest";
-  }
-
-  testD() {
-    print(onlySetter);
-    onlySetter = "hest";
-  }
-}
-
-class D extends C {
-  String get onlySetter() => "D.onlySetter called.";
-
-  void set onlySetter(value) {
-    print("D.onlySetter called with $value.");
-  }
-}
-
-main() {
-  try {
-    print(onlySetter);
-    throw "No error thrown";
-  } on NoSuchMethodError catch (e) {
-    print("Expected error: $e");
-  }
-  onlySetter = "fisk";
-  new C().testC();
-  new D().testD();
-}