Reland "Merge more Kernel infrastructure from kernel_sdk SDK fork."

tests/kernel/unsorted/mapliteral_test.dart

+// Copyright (c) 2016, 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 'expect.dart';
+
+main() {
+  var map = {
+    'k1': 'v1',
+    'k2': 'v2',
+    1: 2,
+    1.5 : 1.2,
+    3: 3.14,
+  };
+
+  Expect.isTrue(map.length == 5);
+
+  map['foo'] = 'bar';
+
+  Expect.isTrue(map['k1'] == 'v1');
+  Expect.isTrue(map['k2'] == 'v2');
+  Expect.isTrue(map[1] == 2);
+  Expect.isTrue(map[1.5] == 1.2);
+  Expect.isTrue(map[3] == 3.14);
+  Expect.isTrue(map['foo'] == 'bar');
+  Expect.isTrue(map.length == 6);
+}