overflowing tokens are now always returned
closes https://github.com/huggingface/transformers/issues/5293

@thomwolf may be superseded by https://github.com/huggingface/transformers/pull/5308/files
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/5310?src=pr&el=h1) Report
> Merging [#5310](https://codecov.io/gh/huggingface/transformers/pull/5310?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/79a82cc06aaa68088639bf9bb000752cfd33a8c6&el=desc) will **increase** coverage by `0.00%`.
> The diff coverage is `0.00%`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/5310/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/5310?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master    #5310   +/-   ##
=======================================
  Coverage   79.29%   79.30%           
=======================================
  Files         138      138           
  Lines       24282    24282           
=======================================
+ Hits        19254    19256    +2     
+ Misses       5028     5026    -2     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/5310?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/data/processors/squad.py](https://codecov.io/gh/huggingface/transformers/pull/5310/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9kYXRhL3Byb2Nlc3NvcnMvc3F1YWQucHk=) | `28.66% <0.00%> (ø)` | |
| [src/transformers/modeling\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5310/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ191dGlscy5weQ==) | `91.14% <0.00%> (-0.13%)` | :arrow_down: |
| [src/transformers/file\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5310/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9maWxlX3V0aWxzLnB5) | `79.59% <0.00%> (+0.33%)` | :arrow_up: |
| [src/transformers/modeling\_tf\_pytorch\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5310/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9weXRvcmNoX3V0aWxzLnB5) | `89.30% <0.00%> (+1.25%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/5310?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/5310?src=pr&el=footer). Last update [79a82cc...5583df5](https://codecov.io/gh/huggingface/transformers/pull/5310?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
<|||||>Yes, it's in #5308 :-)