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

tests/kernel/unsorted/instance_getters_and_setters_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';
+
+class A {
+  var field;
+
+  get getField {
+    return field;
+  }
+
+  set setField(value) {
+    field = value;
+    return null;
+  }
+}
+
+main() {
+  var result;
+  var a = new A();
+
+  Expect.isTrue(a.field == null);
+  Expect.isTrue(a.getField == null);
+
+  result = (a.field = 42);
+  Expect.isTrue(result == 42);
+  Expect.isTrue(a.field == 42);
+  Expect.isTrue(a.getField == 42);
+
+  result = (a.setField = 99);
+  Expect.isTrue(result == 99);
+  Expect.isTrue(a.field == 99);
+  Expect.isTrue(a.getField == 99);
+}