Add corelib tests

test/codegen/corelib/map_keys2_test.dart

Index: test/codegen/corelib/map_keys2_test.dart
diff --git a/test/codegen/corelib/map_keys2_test.dart b/test/codegen/corelib/map_keys2_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..d297c2d77d929ab89532c35223c43550c02c7f40
--- /dev/null
+++ b/test/codegen/corelib/map_keys2_test.dart
@@ -0,0 +1,34 @@
+// 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.
+
+import "package:expect/expect.dart";
+
+main() {
+  var map1 = { "foo": 42, "bar": 499 };
+  var map2 = {};
+  var map3 = const { "foo": 42, "bar": 499 };
+  var map4 = const {};
+  var map5 = new Map<String, int>();
+  map5["foo"] = 43;
+  map5["bar"] = 500;
+  var map6 = new Map<String, bool>();
+
+  Expect.isTrue(map1.keys is Iterable<String>);
+  Expect.isTrue(map1.keys is Iterable<bool>);
+
+  Expect.isTrue(map2.keys is Iterable<String>);
+  Expect.isTrue(map2.keys is Iterable<bool>);
+
+  Expect.isTrue(map3.keys is Iterable<String>);
+  Expect.isTrue(map3.keys is Iterable<bool>);
+
+  Expect.isTrue(map4.keys is Iterable<String>);
+  Expect.isTrue(map4.keys is Iterable<bool>);
+
+  Expect.isTrue(map5.keys is Iterable<String>);
+  Expect.isFalse(map5.keys is Iterable<bool>);
+
+  Expect.isTrue(map6.keys is Iterable<String>);
+  Expect.isFalse(map6.keys is Iterable<bool>);
+}