extern int linux_supports_traceclone (void);
extern int linux_supports_tracevforkdone (void);
extern int linux_supports_tracesysgood (void);
-extern void linux_ptrace_set_additional_flags (int);
extern int linux_ptrace_get_extended_event (int wstat);
extern int linux_is_extended_waitstatus (int wstat);
extern int linux_wstatus_maybe_breakpoint (int wstat);