Issue 5201 - [emscripten] Replace EM_ASM calls by a custom JavaScript library

compiled/subscription/UserDefinedSubscription.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #pragma once
 
+#include <emscripten.h>
+
 #include "Subscription.h"
 #include "../filter/Filter.h"
 
 class UserDefinedSubscription : public Subscription
 {
 private:
   int mDefaults;
 
 public:
   explicit UserDefinedSubscription(const String& id);
   EMSCRIPTEN_KEEPALIVE bool IsDefaultFor(const Filter* filter) const;
   EMSCRIPTEN_KEEPALIVE void MakeDefaultFor(const Filter* filter);
   EMSCRIPTEN_KEEPALIVE void InsertFilterAt(Filter* filter, unsigned pos);
   EMSCRIPTEN_KEEPALIVE bool RemoveFilterAt(unsigned pos);
   EMSCRIPTEN_KEEPALIVE OwnedString Serialize() const;
 };