[js-perf-test] Add RegExp microbenchmarks

test/js-perf-test/RegExp/base_ctor.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.
+
+function SimpleCtor() {
+  new RegExp("[Cz]");
+}
+
+function FlagsCtor() {
+  new RegExp("[Cz]", "guiym");
+}
+
+function SimpleCtorWithoutNew() {
+  RegExp("[Cz]");
+}
+
+function FlagsCtorWithoutNew() {
+  RegExp("[Cz]", "guiym");
+}
+
+function CtorWithRegExpPattern() {
+  new RegExp(/[Cz]/);
+}
+
+function CtorWithRegExpPatternAndFlags() {
+  new RegExp(/[Cz]/, "guiym");
+}
+
+function CtorWithRegExpSubclassPattern() {
+  class SubRegExp extends RegExp {
+    get source() { return "[Cz]"; }
+    get flags() { return "guiym"; }
+  }
+  new RegExp(new SubRegExp(/[Cz]/));
+}
+
+function CtorWithUndefinedPattern() {
+  new RegExp();
+}
+
+function CtorWithFlagsAndUndefinedPattern() {
+  new RegExp(undefined, "guiym");
+}
+
+var benchmarks = [ [SimpleCtor, undefined],
+                   [FlagsCtor, undefined],
+                   [SimpleCtorWithoutNew, undefined],
+                   [FlagsCtorWithoutNew, undefined],
+                   [CtorWithRegExpPattern, undefined],
+                   [CtorWithRegExpPatternAndFlags, undefined],
+                   [CtorWithRegExpSubclassPattern, undefined],
+                   [CtorWithUndefinedPattern, undefined],
+                   [CtorWithFlagsAndUndefinedPattern, undefined],
+                 ];