Add compute_loss_func to Seq2SeqTrainer (huggingface#35136)

Author: d223302

src/transformers/trainer_seq2seq.py

@@ -64,6 +64,7 @@ def __init__(
             Union["PreTrainedTokenizerBase", "BaseImageProcessor", "FeatureExtractionMixin", "ProcessorMixin"]
         ] = None,
         model_init: Optional[Callable[[], "PreTrainedModel"]] = None,
+        compute_loss_func: Optional[Callable] = None,
         compute_metrics: Optional[Callable[["EvalPrediction"], Dict]] = None,
         callbacks: Optional[List["TrainerCallback"]] = None,
         optimizers: Tuple[torch.optim.Optimizer, torch.optim.lr_scheduler.LambdaLR] = (None, None),
@@ -77,6 +78,7 @@ def __init__(
             eval_dataset=eval_dataset,
             processing_class=processing_class,
             model_init=model_init,
+            compute_loss_func=compute_loss_func,
             compute_metrics=compute_metrics,
             callbacks=callbacks,
             optimizers=optimizers,