ref: c1a3310fbbad48582811bb35438f194bbab27c3e dir: /tests/execute/0055-enum.c/
enum E { x, y, z, }; int main() { enum E e; if(x != 0) return 1; if(y != 1) return 2; if(z != 2) return 3; e = x; return e; }