win,test: fix test-stdin-from-file

The test-stdin-from-from-file test runs a subprocess that verifies stdin can be piped from a file.

The subprocess additionally attempts to verify that the file descriptor for stdin never gets closed. It used to do this by creating a TCP server and asserting that the associated file descriptor is greater than two. However this strategy doesn't work on windows, because servers don't have an associated file descriptor. With this patch an ordinary file is opened instead of creating a server.

R=@indutny R=@iojs/platform-windows cc @rvagg