[Bug tree-optimization/121762] pass_fold_builtins and pass_optimize_widening_mul and pass_gimple_isel should be merged or moved other places

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121762

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
> BUILT_IN_CONSTANT_P -> forwprop with late set (zero)

This is actually in the ranger already in cfn_constant_float_p and
cfn_constant_p:
```
    if (lh.singleton_p ())
      {
        wide_int one = wi::one (TYPE_PRECISION (type));
        r.set (type, one, one);
        return true;
      }
    if (cfun->after_inlining)
      {
        r.set_zero (type);
        return true;
      }
```

So this handling also can be removed I think. Unless we think the ranger
folding is too early for this?