/usr/share/postgresql/9.5/extension/plsh.control is in postgresql-9.5-plsh 1.20140221-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | comment = 'PL/sh procedural language'
default_version = 2
relocatable = true
|