All //sys instructions moved to separate syscall_* files

Generated `syscall_*` files ranamed to `zsyscall_*` ones
like it done in `golang.org/x/sys` package.

serial_darwin.go

@@ -11,7 +11,5 @@ import "syscall"
 const devFolder = "/dev"
 const regexFilter = "^(cu|tty)\\..*"
 
-//sys ioctl(fd int, req uint64, data uintptr) (err error)
-
 const ioctlTcgetattr = syscall.TIOCGETA
 const ioctlTcsetattr = syscall.TIOCSETA