Reorganize tests for samples so the test is discoverable from the sample

samples/tests/samples/standalone/build_dart_test.dart

Index: samples/tests/samples/standalone/build_dart_test.dart
diff --git a/samples/tests/samples/standalone/build_dart_test.dart b/samples/tests/samples/standalone/build_dart_test.dart
deleted file mode 100644
index 7106c368ac11325a5eaa410dc283de32f91a8c21..0000000000000000000000000000000000000000
--- a/samples/tests/samples/standalone/build_dart_test.dart
+++ /dev/null
@@ -1,18 +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.
-
-library build_dart_test;
-
-import '../../../build_dart/build.dart' as build_dart;
-import '../../../build_dart/bin/test.dart' as test2;
-
-// @static-clean
-
-/**
- * This test exists to ensure that the build_dart sample compiles without
- * errors.
- */
-void main() {
-
-}