Big merge from experimental to bleeding edge.

tests/corelib/iterable_to_set_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() {
+  List<int> list1 = <int>[1, 2, 3];
+  List<int> list2 = const <int>[4, 4];
+  List<String> list3 = <String>[];
+  Set<int> set1 = new Set<int>();
+  set1..add(11)
+      ..add(12)
+      ..add(13);
+  Set<String> set2 = new Set<String>();
+  set2..add("foo")
+      ..add("bar")
+      ..add("toto");
+  Set set3 = new Set();
+
+  var setCopy = list1.toSet();
+  Expect.equals(3, setCopy.length);
+  Expect.isTrue(setCopy.contains(1));
+  Expect.isTrue(setCopy.contains(2));
+  Expect.isTrue(setCopy.contains(3));
+  Expect.isTrue(setCopy is Set<int>);
+  Expect.isFalse(setCopy is Set<String>);
+
+  setCopy = list2.toSet();
+  Expect.equals(1, setCopy.length);
+  Expect.isTrue(setCopy.contains(4));
+  Expect.isTrue(setCopy is Set<int>);
+  Expect.isFalse(setCopy is Set<String>);
+
+  setCopy = list3.toSet();
+  Expect.isTrue(setCopy.isEmpty);
+  Expect.isTrue(setCopy is Set<String>);
+  Expect.isFalse(setCopy is Set<int>);
+
+  setCopy = set1.toSet();
+  Expect.setEquals(set1, setCopy);
+  Expect.isTrue(setCopy is Set<int>);
+  Expect.isFalse(setCopy is Set<String>);
+  Expect.isFalse(identical(setCopy, set1));
+
+  setCopy = set2.toSet();
+  Expect.setEquals(set2, setCopy);
+  Expect.isTrue(setCopy is Set<String>);
+  Expect.isFalse(setCopy is Set<int>);
+  Expect.isFalse(identical(setCopy, set2));
+
+  setCopy = set3.toSet();
+  Expect.setEquals(set3, setCopy);
+  Expect.isTrue(setCopy is Set<String>);
+  Expect.isTrue(setCopy is Set<int>);
+  Expect.isFalse(identical(setCopy, set3));
+}