BUG #14986: -2147483648 is minimum value of integer but -2147483648::integer fails (out of range).

The following bug has been logged on the website:

Bug reference: 14986
Logged by: Indrek Loolaid
Email address: binoternary(at)gmail(dot)com
PostgreSQL version: 10.1
Operating system: Ubuntu 16.04.3 LTS
Description:

Documentation in
https://www.postgresql.org/docs/current/static/datatype-numeric.html states
that the range for integer type is -2147483648 to +2147483647.

However casting the minimum value literal with :: syntax to integer fails
(ERROR: integer out of range).

postgres=# select version();
version

----------------------------------------------------------------------------------------------------------------
PostgreSQL 10.1 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu
5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609, 64-bit
(1 row)

postgres=# select -2147483648::integer;
ERROR: integer out of range

postgres=# select cast(-2147483648 as integer);
int4
-------------
-2147483648
(1 row)

postgres=# select (select -2147483648)::integer;
?column?
-------------
-2147483648
(1 row)

The expected outome is that the first query returns the same result as the
other two.
Bigint and smallint types have the same issue.