S16 io eof wsl script fudge

[ronaldxs]

See issue #395. Since we change Test::Util run-with-tty we also effect S32-io/out-buffering.t as well as S16-io/eof.t. On WSL/ubuntu 16 out-buffering.t also breaks the terminal but it ran OK on WSL ubuntu 14 since, unlike eof.t, the script process did not read from stdin. Having the out-buffering.t test run on ubuntu 14 does not seem FTM worth a more complicated patch.

[zoffixznet]

👍 Thanks!

If there are any more WSL detections that'd need to be made in roast, we should think about adding some is-OS-WSL utility routine to Test::Util instead of having a long line with $*DISTRO and $*KERNEL each time (or, if there's enough demand, some easier way to detect WSL in Rakudo)