ref: e3c686dd24c18b30bbe1f3c78627a5316a0c8c27 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; }