system: add IsSafe for freebsd
system: add IsSafe for freebsd

sillvan/pond,infinity0/pond,saltthefries/pond,sillvan/pond,ArneBab/pond,ioerror/pond,ioerror/pond,ArneBab/pond,berkus/pond,infinity0/pond,berkus/pond,agl/pond,agl/pond,saltthefries/pond