[rqlrewrite] sort possible types when turning is_instance_of into is
Helps get predictable output even with python -R. Related to #4959402.
#! /bin/sh -e#if [ "$1" = configure ]; then if which install-docs >/dev/null 2>&1; then install-docs -i /usr/share/doc-base/cubicweb-doc fifi#DEBHELPER#exit 0