windows: fall back for volume info query

Julia's build system uses mingw64 and wine for windows packaging. We hit the following issue after rebasing to libuv 0.11.20: Wine [does not](
https://github.com/mirrors/wine/blob/0e42fd97c05beb50c0788164647631c00485623b/dlls/ntdll/file.c#L2679) currently support `pNtQueryVolumeInformationFile` for `FileFsVolumeInformation` (implemented in https://github.com/joyent/libuv/commit/315d7001e8e0a86f30dda68b237d0b25dce48d73 and https://github.com/joyent/libuv/commit/20a8e58adb2a3fc2e92ceb6e1ceb6f05d7e0d439)

This patch checks `io_status` and falls back to previous behavior if the query is not implemented.