[Bug c++/118726] GCC generates wrong code when using non-structured binding declaration as the condition of a for-loop at O2 level

[xiaohuba2021 at 163 dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118726

--- Comment #2 from xiaohuba2021 <xiaohuba2021 at 163 dot com> ---
There is a typo in the code mentioned above. The correct version is:

```
#include <iostream>

int main() {
    volatile int x = 10;
    for (int l = 1; int d = x - l; l = d + 1) {
        int &z = d;
        std::cout << z << '\n';
    }
}
```