rb_fiber_mark_self  312 cont.c         	rb_fiber_mark_self(fib->prev);
rb_fiber_mark_self 2222 vm.c           void rb_fiber_mark_self(rb_fiber_t *fib);
rb_fiber_mark_self 2258 vm.c               rb_fiber_mark_self(th->fiber);
rb_fiber_mark_self 2259 vm.c               rb_fiber_mark_self(th->root_fiber);