[Bug tree-optimization/110931] [14 Regression] Dead Code Elimination Regression since r14-2890-gcc2003cd875

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110931

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Here is one that has always failed due to a similar issue where the inner cast
was removed:
```
void foo(void);
int l=1000;

int main(void)
{
  short t = l;
  int t1 = t;
  if (t1 == 0) {
    signed char b = t1;
    if (b != 1) __builtin_unreachable();
    foo();
  }
}
```