`make check` fails on Windows due to check-sanitycheck

check-sanitycheck.py uses Unix-only module `resource`, `make check` runs `check-sanitycheck` and therefore fails on Windows

```
Traceback (most recent call last):
  File "C:/msys64/home/rust/src/etc/check-sanitycheck.py", line 16, in <module>
    import resource
ImportError: No module named resource
```

Workaround: use `make tidy && make check-notidy` instead of `make check`

cc @richo
