[Bug tree-optimization/118483] Missed optimization due to cast being used more than once

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118483

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Here is a testcase which we miss currently because of the missing optional
convert:
```
short d;
int f(int a)
{
  short b = a;
  int e = ~a;
  short c = e;
  return b == c;
}
```

This is one missing for the `cmp == cmp'` issue too:
```
int f(int a)
{
  return (a == 0) == (a != 0);
}
```