BUG #15634: extension missing

The following bug has been logged on the website:

Bug reference:      15634
Logged by:          ramakrishnan r
Email address:      prakash.ramakrishnan.ap@nielsen.com
PostgreSQL version: 11.1
Operating system:   rhel 7.5
Description:

Hi Team,

We did the yum install PostgreSQL 11.1 on Linux server we facing some
issue.Not able to create the extension only showing below files.

postgres@brurhenppp001.enterprisenet.org:/usr/pgsql-11/share/extension
==> ll
total 12
-rw-r--r--. 1 root root 332 Nov  7 12:36 plpgsql--1.0.sql
-rw-r--r--. 1 root root 179 Nov  7 12:36 plpgsql.control
-rw-r--r--. 1 root root 381 Nov  7 12:36 plpgsql--unpackaged--1.0.sql


npp=# create extension dblink;
ERROR:  could not open extension control file
"/usr/pgsql-11/share/extension/dblink.control": No such file or directory
npp=# create extension file_fdw;
ERROR:  could not open extension control file
"/usr/pgsql-11/share/extension/file_fdw.control": No such file or
directory
npp=# \q


please as soon as possible its production server.