Due to risks known for decades, TIOCSTI now performs no action, and simply

Due to risks known for decades, TIOCSTI now performs no action, and simply
returns EIO.  The base system has been cleaned of TIOCSTI uses (collaboration
between anton and I), and the ports tree appears mostly clean.  A few
stragglers may be discovered and cleaned up later...
In a month or so, we should see if the #define can be removed entirely.
ok anton tedu, support from millert