Expose internal function for converting int64 to numeric
Existing callers had to take complicated detours via
DirectFunctionCall1(). This simplifies a lot of code.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/
42b73d2d-da12-ba9f-570a-
420e0cce19d9@phystech.edu