Big merge from experimental to bleeding edge.

tests/corelib/has_next_iterator_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.
+
+main() {
+  var it = new HasNextIterator([].iterator);
+  Expect.isFalse(it.hasNext);
+  Expect.isFalse(it.hasNext);
+  Expect.throws(() => it.next(), (e) => e is StateError);
+  Expect.isFalse(it.hasNext);
+
+  it = new HasNextIterator([1].iterator);
+  Expect.isTrue(it.hasNext);
+  Expect.isTrue(it.hasNext);
+  Expect.equals(1, it.next());
+  Expect.isFalse(it.hasNext);
+  Expect.isFalse(it.hasNext);
+  Expect.throws(() => it.next(), (e) => e is StateError);
+  Expect.isFalse(it.hasNext);
+
+  it = new HasNextIterator([1, 2].iterator);
+  Expect.isTrue(it.hasNext);
+  Expect.isTrue(it.hasNext);
+  Expect.equals(1, it.next());
+  Expect.isTrue(it.hasNext);
+  Expect.isTrue(it.hasNext);
+  Expect.equals(2, it.next());
+  Expect.isFalse(it.hasNext);
+  Expect.isFalse(it.hasNext);
+  Expect.throws(() => it.next(), (e) => e is StateError);
+  Expect.isFalse(it.hasNext);
+}