Issue 6180 - use ABP_TEXT everywhere in order to let String be a UTF-8 string

compiled/filter/CommentFilter.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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/>.
  */
 
 #include "CommentFilter.h"
 
 ABP_NS_USING
 
 CommentFilter::CommentFilter(const String& text)
     : Filter(classType, text)
 {
 }
 
 Filter::Type CommentFilter::Parse(const String& text)
 {
-  if (text.length() && text[0] == u'!')
+  if (text.length() && text[0] == ABP_TEXT('!'))
     return Type::COMMENT;
   else
     return Type::UNKNOWN;
 }
 
 CommentFilter* CommentFilter::Create(const String& text)
 {
   Type type = Parse(text);
   if (type == Type::COMMENT)
     return new CommentFilter(text);
   else
     return nullptr;
 }