Make reflectClass in dart2js behave appropriately when passed bad arguments

tests/lib/mirrors/reflect_class_test.dart

Index: tests/lib/mirrors/reflect_class_test.dart
diff --git a/tests/lib/mirrors/reflect_class_test.dart b/tests/lib/mirrors/reflect_class_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..c556ba8a93c2831500ca00741481e39e3aba4272
--- /dev/null
+++ b/tests/lib/mirrors/reflect_class_test.dart
@@ -0,0 +1,21 @@
+// 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.
+
+import "dart:mirrors";
+
+import "package:expect/expect.dart";
+
+typedef void FooFunction(int a, double b);
+
+main() {
+  Function expectedError = (e) => e is ArgumentError || e is TypeError;
+
+  Expect.throws(() => reflectClass(dynamic), expectedError);
+  Expect.throws(() => reflectClass(1), expectedError);
+  Expect.throws(() => reflectClass("string"), expectedError);
+
+  // reflectClass() on a function type should fail once typedefs are represented
+  // by TypedefMirrors instead of ClassMirrors.
+  // Expect.throws(() => reflectClass(FooFunction), expectedError);
+}