regr_count should return an int #11726
Description
Describe the bug
regr_count currently returns a Float64.
To Reproduce
DataFusion CLI v40.0.0
> select regr_count(1, 1);
+-------------------------------+
| regr_count(Int64(1),Int64(1)) |
+-------------------------------+
| 1.0 |
+-------------------------------+
1 row(s) fetched.
Elapsed 0.011 seconds.
> select arrow_typeof(regr_count(1, 1));
+---------------------------------------------+
| arrow_typeof(regr_count(Int64(1),Int64(1))) |
+---------------------------------------------+
| Float64 |
+---------------------------------------------+
1 row(s) fetched.
Elapsed 0.001 seconds.
Expected behavior
Consistent with postgres, it should return Int64 or Uint64
https://www.postgresql.org/docs/9.4/functions-aggregate.html
Additional context
No response