Revert "New tests for initializing formal access."

tests/language/initializing_formal_promotion_test.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.
-//
-// DartOptions=--initializing-formal-access
-
-import "package:expect/expect.dart";
-
-class B {}
-
-class A {
-  B x, y;
-  A(this.x) {
-    // Promote to subtype.
-    if (x is C) y = x.x;
-    // Promotion fails, not a subtype.
-    if (x is A) y = x;
-  }
-}
-
-class C extends A implements B {
-  C(B x) : super(x);
-}
-
-main() {
-  C c2 = new C(null);
-  C cc = new C(c2);
-  Expect.equals(c2.y, null);
-  Expect.equals(cc.y, c2);
-}