ref: ca543c97d5f35334bc9784a3b5c7c5a8fe7a8f8a dir: /tests/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; }