More gracefully handle load errors.

lib/src/runner/load_exception_suite.dart

+// Copyright (c) 2015, 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 test.runner.load_exception_suite;
+
+import '../backend/invoker.dart';
+import '../backend/metadata.dart';
+import '../backend/suite.dart';
+import 'load_exception.dart';
+
+/// A test suite generated from a load exception.
+///
+/// Load exceptions are exposed as test suites so that they can be presented
+/// alongside successful tests.
+class LoadExceptionSuite extends Suite {
+  /// The exception that this suite exposes.
+  final LoadException exception;
+
+  LoadExceptionSuite(LoadException exception)
+      : exception = exception,
+        super([
+          new LocalTest("load error", new Metadata(), () => throw exception)
+        ], path: exception.path);
+}