mypy

ab114f3d - [mypyc] Try to fix errors about int32_t on Python 3.5 and Appveyor (#9502)

[mypyc] Try to fix errors about int32_t on Python 3.5 and Appveyor (#9502) Explicitly include `stdint.h`. I'll monitor the Appveyor build to see if this helps. Work on #9501.