[Bug tree-optimization/120280] ABS < 0 is not optimized to false by match

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120280

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
fold_binary_loc does:
```
      /* Convert ABS_EXPR<x> >= 0 to true.  */
      strict_overflow_p = false;
      if (code == GE_EXPR
          && (integer_zerop (arg1)
              || (! HONOR_NANS (arg0)
                  && real_zerop (arg1)))
          && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
        {
          if (strict_overflow_p)
            fold_overflow_warning (("assuming signed overflow does not occur "
                                    "when simplifying comparison of "
                                    "absolute value and zero"),
                                   WARN_STRICT_OVERFLOW_CONDITIONAL);
          return omit_one_operand_loc (loc, type,
                                       constant_boolean_node (true, type),
                                       arg0);
        }

      /* Convert ABS_EXPR<x> < 0 to false.  */
      strict_overflow_p = false;
      if (code == LT_EXPR
          && (integer_zerop (arg1) || real_zerop (arg1))
          && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
        {
          if (strict_overflow_p)
            fold_overflow_warning (("assuming signed overflow does not occur "
                                    "when simplifying comparison of "
                                    "absolute value and zero"),
                                   WARN_STRICT_OVERFLOW_CONDITIONAL);
          return omit_one_operand_loc (loc, type,
                                       constant_boolean_node (false, type),
                                       arg0);
        }
```

Should be easy to port I think.