Add corelib tests

test/codegen/corelib/list_first_test.dart

 // Copyright (c) 2012, 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";
 
-// Test that code motion in the presence of interceptors work in dart2js.
+void test(List list) {
+  if (list.isEmpty) {
+    Expect.throws(() => list.first, (e) => e is StateError);
+  } else {
+    Expect.equals(list[0], list.first);
+  }
+}
 
 main() {
-  var a = [2, '2'];
-  var b = a[1];
-  if (a[0] == 2 && b is String) {
-    Expect.isTrue(b.contains('2'));
-  } else {
-    b.isEven();
-  }
+  test([1, 2, 3]);
+  test(const ["foo", "bar"]);
+  test([]);
+  test(const []);
 }