Revert "Merge more Kernel infrastructure from kernel_sdk SDK fork."

tests/kernel/unsorted/string_concatenation_test.dart

Index: tests/kernel/unsorted/string_concatenation_test.dart
diff --git a/tests/kernel/unsorted/string_concatenation_test.dart b/tests/kernel/unsorted/string_concatenation_test.dart
deleted file mode 100644
index 53eae4e96a472d4f80180a5ada01d05ee5a3c6af..0000000000000000000000000000000000000000
--- a/tests/kernel/unsorted/string_concatenation_test.dart
+++ /dev/null
@@ -1,13 +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 'expect.dart';
-
-class A {
-  toString() => 'hello';
-}
-
-main() {
-  Expect.isTrue('begin ${new A()} end' == 'begin hello end');
-}