Migrate the language tests up to arithmetic_test.

tests/language_strong/abstract_getter2_test.dart

Index: tests/language_strong/abstract_getter2_test.dart
diff --git a/tests/language_strong/abstract_getter2_test.dart b/tests/language_strong/abstract_getter2_test.dart
deleted file mode 100644
index 50a6cafbe3f4411ae1c28b631b59673dc509b0cd..0000000000000000000000000000000000000000
--- a/tests/language_strong/abstract_getter2_test.dart
+++ /dev/null
@@ -1,29 +0,0 @@
-// 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.
-
-import "package:expect/expect.dart";
-
-class A {
-  int get x => 100;
-}
-
-abstract class B extends A {
-  int _x;
-
-  int get x;
-  set x(int v) {
-    _x = v;
-  }
-}
-
-class C extends B {
-  int get x => super.x;
-}
-
-void main() {
-  B b = new C();
-  b.x = 42;
-  Expect.equals(b._x, 42);
-  Expect.equals(b.x, 100);
-}