message: work around DPC++ use-after-free
diff: @@ -102,6 +102,7 @@ void DpcppExecutor::populate_exec_info(const MachineTopology *mach_topo)
  void DpcppExecutor::raw_free(void *ptr) const noexcept
  {
  + queue_->wait_and_throw();
  sycl::free(ptr, queue_->get_context());
  }
  