Add support for field initialization in objects

pkg/kernel/testcases/interpreter/object_initializers_test.dart

-// Copyright (c) 2017, 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.
-
-library object_initializers_test;
-
-/// Simple program creating an object with field initializers.
-void main() {
-  var a = new A('foo1', 'foo2');
-  print(a.foo1);
-  print(a.foo2);
-
-  var b = new B(fieldInitializer(0, 'foo1'), fieldInitializer(0, 'foo2'));
-  print(b.foo1);
-  print(b.foo2);
-  print(b.foo3);
-}
-
-class A {
-  String foo1;
-  String foo2;
-
-  A(String foo1, String foo2)
-      : foo1 = foo1,
-        foo2 = foo2;
-}
-
-class B {
-  String foo1 = fieldInitializer(1, 'foo1');
-  String foo2 = fieldInitializer(1, 'foo2');
-  String foo3 = fieldInitializer(1, 'foo3');
-
-  B(this.foo1, this.foo2) : foo3 = foo2;
-}
-
-String fieldInitializer(int f, String s) {
-  print('$s: $f');
-  return '$s: $f';
-}