Revert "Change the negative tests called language/deferred* to multitests."

tests/language/deferred_no_prefix_test.dart

Index: tests/language/deferred_no_prefix_test.dart
diff --git a/tests/language/deferred_no_prefix_test.dart b/tests/language/deferred_no_prefix_test.dart
deleted file mode 100644
index 3fed27b2f70fc5e183cd898698ecdcbb848288b4..0000000000000000000000000000000000000000
--- a/tests/language/deferred_no_prefix_test.dart
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright (c) 2014, 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 "dart:async";
-
-// Loading a deferred library without prefix is not allowed.
-@lazy import "deferred_constraints_lib2.dart"; /// 01: compile-time error
-
-const lazy = const DeferredLibrary('lib');
-
-void main() {}