This is needed for the docs generator to generate all the docs for the
posix package, if it is imported like it was on Windows it would
generate docs for the Windows version of the package which has much less
symbols exposed.
A thread made inside a test does not share the test index of its parent,
so any time one of those threads failed an assert, it would tell the
runner to shutdown test index zero.
Currently, a Ctrl+c starts a graceful shutdown of the tests and runner.
Sometimes tests get stuck and this would never complete.
This simply adds an extra step, if Ctrl+c is given for the second time,
just `os.exit` right away.
