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

tests/language/deferred_duplicate_prefix3_negative_test.dart

Index: tests/language/deferred_duplicate_prefix3_negative_test.dart
diff --git a/tests/language/deferred_duplicate_prefix3_negative_test.dart b/tests/language/deferred_duplicate_prefix3_negative_test.dart
deleted file mode 100644
index db66724a2a5ad334891a6d9aa1a026435746656a..0000000000000000000000000000000000000000
--- a/tests/language/deferred_duplicate_prefix3_negative_test.dart
+++ /dev/null
@@ -1,13 +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";
-
-@lazy import "deferred_constraints_lib.dart" as lib;
-@lazy2 import "deferred_constraints_lib2.dart" as lib;
-
-const lazy = const DeferredLibrary('lib');
-const lazy2 = const DeferredLibrary('lib2');
-
-void main() {}