[pypy-issue] Issue #2757: Can't import asyncio on Windows, ImportError: cannot import name '_overlapped' (pypy/pypy)

[Wonderless]

New issue 2757: Can't import asyncio on Windows, ImportError: cannot import name '_overlapped'
https://bitbucket.org/pypy/pypy/issues/2757/cant-import-asyncio-on-windows-importerror

Wonderless:

Took [Windows binary](https://bitbucket.org/pypy/pypy/downloads/pypy3-v5.10.1-win32.zip) from the download page, didn't change anything, plain `import asyncio` fails.
```
Python 3.5.3 (3f6eaa010fce, Jan 11 2018, 04:46:12)
[PyPy 5.10.1 with MSC v.1500 32 bit] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>> import asyncio
Traceback (most recent call last):
  File "t:\pypy3-v5.10.1-win32\lib-python\3\asyncio\__init__.py", line 16, in <module>
    from . import _overlapped
ImportError: cannot import name '_overlapped'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "t:\pypy3-v5.10.1-win32\lib-python\3\asyncio\__init__.py", line 18, in <module>
    import _overlapped  # Will also be exported.
ImportError: No module named '_overlapped'
```