include mypyc subdirectories in the sdist

[mr-c]

Needed for the Debian package of mypy as we use mypyc during building.

[mr-c]

Originally I was going to patch in the missing files, when I thought it was just one directory. Now it is a lot of directories, so with my Debian hat on I would like to request a 0.781 release with this fix.

Thanks, as always, for such a great project!

[mr-c]

I can contribute a test for this error, if that would be welcome.

[msullivan]

A test with that error would be fantastic, because we mess this up a lot >_>

@ilevkivskyi what do you think about a point release?

[ilevkivskyi]

Yes, I will release 0.781 tomorrow. What exactly should I cherry-pick? Just this PR?

[mr-c]

FYI, one cannot pip install mypy in Python 3.9 and have mypyc working as there is no binary wheel for mypy 0.780 for Python 3.9 yet

[msullivan]

FYI, one cannot pip install mypy in Python 3.9 and have mypyc working as there is no binary wheel for mypy 0.780 for Python 3.9 yet

There's still a none wheel, though, right?

[mr-c]

There's still a none wheel, though, right?

The none wheel for 0.780 is missing the same sub-directories under mypyc/ as the sdist is 🥺

[mr-c]

@ilevkivskyi 0.781 should also include 4d9a07d

[ilevkivskyi]

I already released 0.781 without this one. We are however thinking about 0.782 (for couple other fixes), so we will include it there.