ptrace_report_clone() still needs more changes. I think it is simple to
fix it now, but can't we simplify the utrace's behaviour first?
utrace_report_clone() does not set utrace-vfork_stop without CLONE_VFORK,
this adds some complications. Perhaps we can kill CLONE_VFORK check?
Please
PTRACE_EVENT_VFORK_DONE should not be reported if the tracer cleared
PTRACE_O_TRACEVFORKDONE after the tracee stopped in PTRACE_EVENT_VFORK
report. Now that we have ptrace_event-ev_options this is trivial.
ptrace_report_clone() still needs more changes. I think it is simple to
fix it now, but
