Move kernel baseline tests to front_end.

pkg/front_end/test/fasta/fibonacci.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.
-
-int fibonacci(int n) {
-  if (n < 2) return n;
-  return fibonacci(n - 1) + fibonacci(n - 2);
-}
-
-main() {
-  for (int i = 0; i < 20; i++) {
-    print(fibonacci(i));
-  }
-}