Windows: failing unit tests in libstd\rt\uvio.rs

[vadimcn]

test_udp_twice (hangs)
file_test_uvio_full_simple
task <unnamed> failed at 'called Result::unwrap()onErr value: IoError { kind: PermissionDenied, desc: permission denied, detail: None }', C:\Rust\src\libstd\result.rs:120