Function concat

include/cpp/VirtualArray.h:471–478

   Dynamic shift() { checkBase(); return store==hx::arrayEmpty ? null() : base->__shift(); }

   VirtualArray concat( VirtualArray inTail )
   {
      inTail->checkBase();
      EnsureArrayStorage(inTail);
      if (inTail->__length()<1)
         return copy();
      return new VirtualArray_obj( base->__concat(inTail), store==hx::arrayFixed );
   }
   VirtualArray copy( )
   {
      checkBase();