Move kernel baseline tests to front_end.

pkg/front_end/test/fasta/rasta/unresolved_recovery.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.
-
-class E {
-  foo() {
-    super[4] = 42;
-    super[4] += 5;
-    return super[2];
-  }
-}
-
-beforeTestMissingTry () {
-  // Referring to this function before it has been resolved would lead to a
-  // crash.
-  testMissingTry();
-}
-
-testMissingTry() {
-  on Exception catch (e) { }
-}
-
-main() {
-}