ref: ff5b36e280ae269eaa3835006f0f46fbe1bb2d2f dir: /tests/cc/execute/0037-assignop.c/
int main() { int x; x = 0; x += 2; x += 2; if (x != 4) return 1; x -= 1; if (x != 3) return 2; x *= 2; if (x != 6) return 3; return 0; }