VM_CALL_TAILCALL 2295 compile.c      		    ci->flag |= VM_CALL_TAILCALL;
VM_CALL_TAILCALL 2299 compile.c      		ci->flag |= VM_CALL_TAILCALL;
VM_CALL_TAILCALL 1342 iseq.c         		if (ci->flag & VM_CALL_TAILCALL) rb_ary_push(flags, rb_str_new2("TAILCALL"));
VM_CALL_TAILCALL 1390 vm_insnhelper.c     if (LIKELY(!(ci->flag & VM_CALL_TAILCALL))) {