message: Return an error instead of crashing
  The function returns a Status so we can just propagate the stream error.
diff: @@ -80,8 +80,8 @@ Status TpuTransferAsyncOpKernelBase::RunTransferWithOrdinal(
  TF_RETURN_IF_ERROR(XlaDevice::GetMetadata(ctx, &metadata));
  real_device_ordinal = metadata->device_ordinal();
  }
  - stream_executor::StreamExecutor* stream_executor =
  - tpu_platform->ExecutorForDevice(real_device_ordinal).ValueOrDie();
  + TF_ASSIGN_OR_RETURN(stream_executor::StreamExecutor * stream_executor,
  + tpu_platform->ExecutorForDevice(real_device_ordinal));
  profiler::TraceMe activity(
  [real_device_ordinal] {
  