[es6] implement spread calls

test/js-perf-test/SpreadCalls/spreadcalls.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.
+
+new BenchmarkSuite('Call', [1000], [
+  new Benchmark('Call-Sum', false, false, 0,
+                CallSum, CallSumSetup,
+                CallSumTearDown),
+]);
+
+new BenchmarkSuite('CallMethod', [1000], [
+  new Benchmark('CallMethod-Sum', false, false, 0,
+                CallMethodSum, CallSumSetup, CallMethodSumTearDown),
+]);
+
+new BenchmarkSuite('CallNew', [1000], [
+  new Benchmark('CallNew-Sum', false, false, 0,
+                CallNewSum, CallSumSetup,
+                CallNewSumTearDown),
+]);
+
+var result;
+var objectToSpread;
+
+function sum() {
+  var result = arguments[0];
+  for (var i = 1; i < arguments.length; ++i) {
+    result += arguments[i];
+  }
+  return result;
+}
+
+function CallSumSetup() {
+  result = undefined;
+  objectToSpread = [];
+  for (var i = 0; i < 100; ++i) objectToSpread.push(i + 1);
+}
+
+function CallSum() {
+  result = sum(...objectToSpread);
+}
+
+function CallSumTearDown() {
+  var expected = 100 * (100 + 1) / 2;
+  return result === expected;
+}
+
+// ----------------------------------------------------------------------------
+
+var O = { sum: sum };
+function CallMethodSum() {
+  result = O.sum(...objectToSpread);
+}
+
+function CallMethodSumTearDown() {
+  var expected = 100 * (100 + 1) / 2;
+  return result === expected;
+}
+
+// ----------------------------------------------------------------------------
+
+function Sum() {
+  var result = arguments[0];
+  for (var i = 1; i < arguments.length; ++i) {
+    result += arguments[i];
+  }
+  return this.sum = result;
+}
+
+function CallNewSum() {
+  result = new Sum(...objectToSpread);
+}
+
+function CallNewSumTearDown() {
+  var expected = 100 * (100 + 1) / 2;
+  return result instanceof Sum && result.sum === expected;
+}