Setup loss_type in config at model init time
Author: ChanderG
Pull request: yes
Labels: name: Compilation

ensures no additional graph break introduced when torch.compile'ed

fixes #34615

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Comments:
If this approach is fine - I will extend the PR to cover a wide set of models.

A more generic option may be to run the regex call at model init time, instead of hardcoding. I need to check, but it may still be efficient placed there (ie, won't cause a graph break from init).

@ArthurZucker Updated to generic lookup. Tested with the repro here https://github.com/huggingface/transformers/issues/34615#issuecomment-2482082014 and no Graph Breaks with this latest version as well.

Waiting on this to put in the upcoming release !! 🤗 

Okay this is failing tests because the `loss_type` is stored in the `config`, which is not reset in the tests. 
It is actually be better to store the `loss_type` in the `PreTrainedModel` rather than in the config!

Pushed directly, hope it's not a problem 🤗 wanted to get this fix in fast! 

Thanks for your patience! I thought this had been merged a while ago!