[PyTorch] Refactor Resize Token Embeddings (#8880)

* fix resize tokens

* correct mobile_bert

* move embedding fix into modeling_utils.py

* refactor

* fix lm head resize

* refactor

* break lines to make sylvain happy

* add news tests

* fix typo

* improve test

* skip bart-like for now

* check if base_model = get(...) is necessary

* clean files

* improve test

* fix tests

* revert style templates

* Update templates/adding_a_new_model/cookiecutter-template-{{cookiecutter.modelname}}/modeling_{{cookiecutter.lowercase_modelname}}.py

tests/test_modeling_reformer.py

@@ -574,6 +574,10 @@ class ReformerTesterMixin:
         # reformer cannot keep gradients in attentions or hidden states
         return
 
+    def test_resize_embeddings_untied(self):
+        # reformer cannot resize embeddings that easily
+        return
+
 
 @require_torch
 class ReformerLocalAttnModelTest(ReformerTesterMixin, GenerationTesterMixin, ModelTesterMixin, unittest.TestCase):