Remove deprecated packages from pkg directory.

pkg/collection_helpers/lib/all.dart

Index: pkg/collection_helpers/lib/all.dart
diff --git a/pkg/collection_helpers/lib/all.dart b/pkg/collection_helpers/lib/all.dart
deleted file mode 100644
index a9f6b63f1d0aa2358c4965089ad7ac529666d476..0000000000000000000000000000000000000000
--- a/pkg/collection_helpers/lib/all.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2013, 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.
-
-@deprecated
-library dart.collection_helper;
-
-export "algorithms.dart";
-export "equality.dart";
-export "typed_buffers.dart";
-export "wrappers.dart";