[Bug tree-optimization/114999] A few missing optimizations due to `a - b` and `b - a` not being detected as negatives of each other

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114999

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The following patterns could be improved/removed while doing this:
```
 /* (A - B) == 0 ? (A - B) : (B - A)    same as (B - A) */
 /* (A - B) != 0 ? (A - B) : (B - A)    same as (A - B) */
 /* (A - B) >=/> 0 ? (A - B) : (B - A)    same as abs (A - B) */
 /* (A - B) <=/< 0 ? (A - B) : (B - A)    same as -abs (A - B) */

```

Need to look if we need to improve ctz_table_index match.