Add UseCounters for various standards-related code paths

src/js/harmony-unicode-regexps.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.
 
 (function(global, utils) {
 
 'use strict';
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
 // Imports
 
 var GlobalRegExp = global.RegExp;
 var GlobalRegExpPrototype = GlobalRegExp.prototype;
 var MakeTypeError;
 
 utils.Import(function(from) {
   MakeTypeError = from.MakeTypeError;
 });
 
 // -------------------------------------------------------------------
 
 // ES6 21.2.5.15.
 function RegExpGetUnicode() {
   if (!IS_REGEXP(this)) {
+    if (this === GlobalRegExpPrototype) {
+      %IncrementUseCounter(kRegExpPrototypeUnicodeGetter);
+    }
     throw MakeTypeError(kRegExpNonRegExp, "RegExp.prototype.unicode");
   }
   return !!REGEXP_UNICODE(this);
 }
 %FunctionSetName(RegExpGetUnicode, "RegExp.prototype.unicode");
 %SetNativeFlag(RegExpGetUnicode);
 
 utils.InstallGetter(GlobalRegExp.prototype, 'unicode', RegExpGetUnicode);
 
 })