Access to imports in the VM's runtime mirrors. Extend test coverage of the source mirrors.

tests/lib/mirrors/library_imports_bad_metadata_test.dart

+// 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.
+
+library test.library_imports_bad_metadata;
+
+@undefined  /// 01: compile-time error
+import 'dart:mirrors';
+import 'package:expect/expect.dart';
+
+main() {
+  LibraryMirror thisLibrary =
+      currentMirrorSystem().findLibrary(#test.library_imports_bad_metadata);
+
+  thisLibrary.libraryDependencies.forEach((dep) {
+    Expect.listEquals([], dep.metadata);
+  });
+}