This replaces 0 and 1 with STDIN_FILENO and STDOUT_FILENO to make the intention of the code clearer.
This is run with uncrustify 0.70.1, and black 19.10b0.
This is to keep the top-level directory clean, to make it clear what is core and what is a port, and to allow the repository to grow with new ports in a sustainable way.