Summary:
In Windows, a socket is not a file descriptor. So passing it to
setmode/isatty causes an error that returns EABF and triggers invalid
parameter handler.

Test Plan:
1. Add WinDbg as a postmortem debugger (C:\>windbg -I)
2. Pass a socket to GHC.IO.Device.IODevice.isTerminal / GHC.IO.FD.fdToHandle'  (Executing 'cabal update' calls each functions with the socket in cabal-install 1.20.0.1)
3. WinDbg pops up and outputs error message: "Invalid parameter passed to C runtime function."
4. Apply the patch
5. Redo step 2
6. WinDbg doesn't pop up

Reviewers: austin

Reviewed By: austin

Subscribers: phaskell, simonmar, relrod, carter

Differential Revision: https://phabricator.haskell.org/D92