`gcd` returns negative results

[jonahgao]

Describe the bug

According to the Binary GCD algorithm, its result cannot be a negative number.

To Reproduce

DataFusion CLI v39.0.0
> select gcd(-100, 0), gcd(0, -100);
+---------------------------+---------------------------+
| gcd(Int64(-100),Int64(0)) | gcd(Int64(0),Int64(-100)) |
+---------------------------+---------------------------+
| -100                      | -100                      |
+---------------------------+---------------------------+

Expected behavior

In PostgreSQL

postgres=# select gcd(-100, 0), gcd(0, -100);
 gcd | gcd
-----+-----
 100 | 100
(1 row)

Additional context

No response

[LorrensP-2158466]

I really thought this was fixed, I think we introduced this because we moved the unsigned_abs after the checks on 0. good catch!