[test] Add object literal micro-benchmarks.

test/js-perf-test/SixSpeed/ObjectLiterals/ObjextLiterals.js

+// Copyright 2016 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.
+
+// This benchmark is based on the six-speed benchmark build output.
+// Copyright 2014 Kevin Decker <https://github.com/kpdecker/six-speed/>
+
+
+new BenchmarkSuite('ObjectLiterals-ES5', [1000], [
+  new Benchmark('ES5', false, false, 0, ES5),
+]);
+
+new BenchmarkSuite('ObjectLiterals-ES6', [1000], [
+  new Benchmark('ES6', false, false, 0, ES6),
+]);
+
+// ----------------------------------------------------------------------------
+// Benchmark: ES5
+// ----------------------------------------------------------------------------
+
+function ES5() {
+  "use strict";
+  var name = 'foo';
+  var ret = {};
+  ret[name] = 'bar';
+  return ret;
+}
+
+
+// ----------------------------------------------------------------------------
+// Benchmark: ES6
+// ----------------------------------------------------------------------------
+
+function ES6() {
+  "use strict";
+  var name = 'foo';
+  var ret = {
+    [name]: 'bar',
+  };
+  return ret;
+}