BUG #18094: max max_connections cannot be set

The following bug has been logged on the website:

Bug reference:      18094
Logged by:          Nikolay Samokhvalov
Email address:      nikolay@samokhvalov.com
PostgreSQL version: 15.4
Operating system:   MacOS
Description:

(apologies for double posting, please disregard the previous message)

Expectation for max max_connections is 262143 in PG14, but it cannot be
achieved:

nik=# select version();
                                                             version

---------------------------------------------------------------------------------------------------------------------------------
 PostgreSQL 15.4 (Homebrew) on aarch64-apple-darwin22.4.0, compiled by Apple
clang version 14.0.3 (clang-1403.0.22.14.1), 64-bit
(1 row)

nik=# select max_val from pg_settings where name = 'max_connections';
 max_val
---------
 262143
(1 row)

nik=# alter system set max_connections to 262143;
ERROR:  invalid value for parameter "max_connections": 262143
nik=# alter system set max_connections to 262142;
ERROR:  invalid value for parameter "max_connections": 262142
nik=# alter system set max_connections to 262140;
ERROR:  invalid value for parameter "max_connections": 262140
nik=# alter system set max_connections to 262135;
ERROR:  invalid value for parameter "max_connections": 262135
nik=# alter system set max_connections to 262130;
ERROR:  invalid value for parameter "max_connections": 262130
nik=# alter system set max_connections to 262100;
ALTER SYSTEM