These were once needed for sig_atomic_t, but that no longer appears in
these headers, so the include is not needed.
Reviewed-by: Shubham Khanna <Shubham.Khanna@fujitsu.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/
cff5475d-e0a9-4561-b094-
794aa36bd031%40eisentraut.org