Add corelib tests

test/codegen/corelib/hash_map_test.dart

+// 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.
+//
+// VMOptions=
+// VMOptions=--use_internal_hash_map
+
+import "package:expect/expect.dart";
+
+// Test program for the HashMap class.
+
+class HashMapTest {
+
+  static testMain() {
+    var m = new Map();
+    Expect.equals(0, m.length);
+    Expect.equals(true, m.isEmpty);
+    m["one"] = 1;
+    Expect.equals(1, m.length);
+    Expect.equals(false, m.isEmpty);
+    Expect.equals(1, m["one"]);
+  }
+}
+
+main() {
+  HashMapTest.testMain();
+}