[js-perf-test] Add RegExp microbenchmarks

test/js-perf-test/RegExp/base_split.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.
+
+load("base.js");
+
+var str;
+var re;
+
+function SimpleSplit() {
+  str.split(re);
+}
+
+function Split1Setup() {
+  re = /[Cz]/;
+  str = createHaystack();
+}
+
+function Split2Setup() {
+  re = /[Cz]/u;
+  str = createHaystack();
+}
+
+function Split3Setup() {
+  re = /[Cz]/y;
+  str = createHaystack();
+}
+
+function Split4Setup() {
+  re = /[Cz]/uy;
+  str = createHaystack();
+}
+
+function Split5Setup() {
+  re = /[Cz]/;
+  str = "";
+}
+
+function Split6Setup() {
+  re = /[cZ]/;  // No match.
+  str = createHaystack();
+}
+
+function Split7Setup() {
+  re = /[A-Za-z\u0080-\u00FF ]/;
+  str = "hipopótamo maçã pólen ñ poção água língüa";
+}
+
+var benchmarks = [ [SimpleSplit, Split1Setup],
+                   [SimpleSplit, Split2Setup],
+                   [SimpleSplit, Split3Setup],
+                   [SimpleSplit, Split4Setup],
+                   [SimpleSplit, Split5Setup],
+                   [SimpleSplit, Split6Setup],
+                   [SimpleSplit, Split7Setup],
+                 ];