/usr/share/debhelper/autoscripts/postinst-clc-implementation is in dh-lisp 0.7.1+nmu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 | case "$1" in
    configure)
	    if [ -x /usr/lib/common-lisp/bin/"#IMPLEMENTATION#.sh" ] &&
		which register-common-lisp-implementation > /dev/null; then
		register-common-lisp-implementation "#IMPLEMENTATION#"
	    fi
	    ;;
    abort-upgrade|abort-remove|abort-deconfigure)
	    if which register-common-lisp-implementation > /dev/null; then
		unregister-common-lisp-implementation "#IMPLEMENTATION#"
	    fi
	    ;;
esac
 |