Removed __div__ impls from Cython
Alternate to #34711 which may close #34704
I believe failure is unrelated. Looking into it but @jbrockmendel might have some ideas as well given his comment here ref #33858:

https://github.com/pandas-dev/pandas/blob/08febd2b9f77fd8f943de92939788e8bc53ee2d2/pandas/tests/extension/base/dtype.py#L78 Nevermind had the wrong PR. Looks like it _might_ trace back to #22699 hmm what is this needed for? These throw unused function warnings / errors in newer Cython versions during compilation 

Sent from my iPhone

> On Jun 14, 2020, at 7:36 AM, Jeff Reback <notifications@github.com> wrote:
> 
> ﻿
> hmm what is this needed for?
> 
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 thanks @MeeseeksDev backport to 1.0.x Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
$ git checkout 1.0.x
$ git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
$ git cherry-pick -m1 7240ed459e60c91e706940a0db72228c3c70beeb
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
$ git commit -am 'Backport PR #34718: Removed __div__ impls from Cython'
```

4. Push to a named branch :

```
git push YOURFORK 1.0.x:auto-backport-of-pr-34718-on-1.0.x
```

5. Create a PR against branch 1.0.x, I would have named this PR:

> "Backport PR #34718 on branch 1.0.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 xref #34802