While the underlying getaddrinfo call accepts a null pointer for
the hintp parameter, pg_getaddrinfo_all does not. Document this
difference with a comment to make it clear.
Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Sergey Tatarintsev <s.tatarintsev@postgrespro.ru>
Discussion: https://postgr.es/m/1e5efc94-407e-40b8-8b10-4d25f823c6d7@postgrespro.ru