Method compareExchange

include/hx/StdLibs.h:534–547

   }

   Dynamic compareExchange(Dynamic expected, Dynamic replacement) {
     // Note: using Dynamic instead of hx::Object* is important
     // Dynamic has an overloaded == operator, a raw pointer to hx::Object does not.
     Dynamic original = aPtr.load();
     while (original == expected) {
       if (aPtr.compare_exchange_weak(original.mPtr, replacement.mPtr)) {
         HX_OBJ_WB_GET(this, replacement.mPtr);
         return original;
       } else {
         continue;
       }
     }
     return original;
   }
};

inline Dynamic __hxcpp_atomic_object_create(Dynamic value) {