Add test for Object.dynamic.

tests/language/src/ObjectDynamicMethodTest.dart

Index: tests/language/src/ObjectDynamicMethodTest.dart
diff --git a/tests/language/src/ObjectDynamicMethodTest.dart b/tests/language/src/ObjectDynamicMethodTest.dart
new file mode 100644
index 0000000000000000000000000000000000000000..96e16b90472053d477472285a89cce2d7c75380a
--- /dev/null
+++ b/tests/language/src/ObjectDynamicMethodTest.dart
@@ -0,0 +1,33 @@
+// Copyright (c) 2011, 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.
+
+// Test that Object.dynamic returns the identical object.
+
+main() {
+  // Primitives
+  var anInt = 5;
+  var aString = 'Hello';
+  var aBool = true;
+  var aDouble = 3.14159;
+
+  // Compounds
+  var aMap = {};
+
+  // The type should not change.
+  Expect.isTrue(dyn(anInt) is int, 'is int');
+  Expect.isTrue(dyn(aString) is String, 'is String');
+  Expect.isTrue(dyn(aBool) is bool, 'is bool');
+  Expect.isTrue(dyn(aMap) is Map, 'is Map');
+
+  // The object should be identical.
+  Expect.isTrue(eq(anInt, anInt.dynamic), 'anInt.dynamic');
+  Expect.isTrue(eq(aString, aString.dynamic), 'aString.dynamic');
+  Expect.isTrue(eq(aBool, aBool.dynamic), 'aBool.dynamic');
+  Expect.isTrue(eq(aDouble, aDouble.dynamic), 'aDouble.dynamic');
+  Expect.isTrue(eq(aMap, aMap.dynamic), 'aMap.dynamic');
+}
+
+dyn(x) => x.dynamic;
+
+eq(a, b) => a === b;