Move js perf test to another directory.

test/js-perf-test/Collections/set.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('Set', [1000], [
   new Benchmark('Add', false, false, 0, SetAdd),
   new Benchmark('Has', false, false, 0, SetHas, SetSetup, SetTearDown),
   new Benchmark('Delete', false, false, 0, SetDelete, SetSetup, SetTearDown),
   new Benchmark('ForEach', false, false, 0, SetForEach, SetSetup, SetTearDown),
@@ skipping 46 matching lines @@
 }
 
 
 function SetForEach() {
   set.forEach(function(v, k) {
     if (v !== k) {
       throw new Error();
     }
   });
 }