ref: c91781cb539c8c8d9bf20a37671f3451e24eb8ea dir: /tests/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; }