_WaitHandleFuture now unregisters its wait handler if WaitForSingleObject() raises an exception.
_WaitHandleFuture now unregisters its wait handler if WaitForSingleObject()
raises an exception.

vxgmichel/asyncio,jashandeep-sohi/asyncio,manipopopo/asyncio,Martiusweb/asyncio,gvanrossum/asyncio,ajdavis/asyncio,manipopopo/asyncio,gsb-eng/asyncio,Martiusweb/asyncio,fallen/asyncio,ajdavis/asyncio,1st1/asyncio,vxgmichel/asyncio,haypo/trollius,jashandeep-sohi/asyncio,manipopopo/asyncio,ajdavis/asyncio,1st1/asyncio,Martiusweb/asyncio,fallen/asyncio,jashandeep-sohi/asyncio,vxgmichel/asyncio,haypo/trollius,gvanrossum/asyncio,fallen/asyncio,gsb-eng/asyncio,gvanrossum/asyncio,1st1/asyncio,gsb-eng/asyncio,haypo/trollius