`nanvl` incorrectly rounds on integer input

[neilconway]

Describe the bug

> select nanvl(16777217, 1), nanvl(16777217.0, 1);
+---------------------------------+-----------------------------------+
| nanvl(Int64(16777217),Int64(1)) | nanvl(Float64(16777217),Int64(1)) |
+---------------------------------+-----------------------------------+
| 16777216.0                      | 16777217.0                        |
+---------------------------------+-----------------------------------+
1 row(s) fetched.
Elapsed 0.002 seconds.

To Reproduce

No response

Expected behavior

No response

Additional context

No response

[neilconway]

take