ref: b655b713cf6cb7abb87ef704b3dc24f91d7b2b3e dir: /tests/cc/execute/0043-union.c/
int main() { union { int a; int b; } u; u.a = 1; u.b = 3; if (u.a != 3 || u.b != 3) return 1; return 0; }