ref: 5cee3c5e3fdc511a468879104c08a1aa0e8c2b0f dir: /tests/cc/execute/0019-selfrefstruct.c/
int main() { struct S { struct S *p; int x; } s; s.x = 0; s.p = &s; return s.p->p->p->p->p->x; }