[es6] implement Object.assign

test/perf-test/Object/assign.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+
+var SetBenchmark = new BenchmarkSuite('ObjectAssign', [1000], [
+  new Benchmark('ObjectAssignSimple2', false, false, 0, ObjectAssignSimple2Test, ObjectAssignSimple2Setup, ObjectAssignSimple2TearDown),
+]);
+
+
+var target;
+var source1;
+var source2;
+
+function ObjectAssignSimple2Setup() {
+  // Based on http://jsperf.com/extend-vs-defaults/
+  target = {};
+  source1 = {
+    one: true,
+    two: true,
+    three: true,
+    four: true
+  };
+  source2 = {
+    one: false,
+    two: false,
+    five: true
+  };
+}
+
+
+function ObjectAssignSimple2TearDown() {
+  source1 = source2 = target = null;
+}
+
+
+function ObjectAssignSimple2Test() {
+  Object.assign(target, source2, source1);
+}