[js-perf-test] Add RegExp microbenchmarks

test/js-perf-test/RegExp/base_replace.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 StringReplace1() {
+  str.replace(re, "");
+}
+
+function StringReplace2() {
+  str.replace(re, "xyz");
+}
+
+function StringReplace3() {
+  str.replace(re, "x$1yz");
+}
+
+function FunctionReplace1() {
+  str.replace(re, String);
+}
+
+function Replace1Setup() {
+  re = /[Cz]/;
+  str = createHaystack();
+}
+
+function Replace2Setup() {
+  re = /[Cz]/g;
+  str = createHaystack();
+}
+
+function Replace3Setup() {
+  re = /([Cz])/;
+  str = createHaystack();
+}
+
+function Replace4Setup() {
+  re = /([Cz])/g;
+  str = createHaystack();
+}
+
+var benchmarks = [ [ StringReplace1, Replace1Setup],
+                   [ StringReplace1, Replace2Setup],
+                   [ StringReplace2, Replace1Setup],
+                   [ StringReplace2, Replace2Setup],
+                   [ StringReplace3, Replace3Setup],
+                   [ StringReplace3, Replace4Setup],
+                   [ FunctionReplace1, Replace3Setup],
+                   [ FunctionReplace1, Replace4Setup],
+                 ];