[Bug tree-optimization/113176] `(n / 4) ? n / 4 : 0` is not optimized to just `n /4`

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113176

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I should note the non-constant case is already handled:
```
int unopt(int n, int c) {
    if (n / c)
        return n / c;
    else
        return 0;
}
```
It is just the constant case that has issues.