CALLER_BINDING_SELF 1111 vm_backtrace.c     rb_ary_store(frame, CALLER_BINDING_SELF, cfp->self);
CALLER_BINDING_SELF 1126 vm_backtrace.c     rb_ary_store(frame, CALLER_BINDING_SELF, cfp->self);
CALLER_BINDING_SELF 1213 vm_backtrace.c     return rb_ary_entry(frame, CALLER_BINDING_SELF);