[Bug tree-optimization/112659] missed-optimization: if (exp) return exp; else return 0;

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112659

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Vector testcase (C++ only) for the missing add case:
```
#define vector4 __attribute__((vector_size(4*sizeof(int))))

void unopt(vector4 int *v) {
    vector4 int t = *v;
    vector4 int t1 = t + 8;
    *v = (t != -8) ? (t1) : 0;
}
```

Adding it here so I don't lose it (note clang/LLVM does catch it already).