lablst-pkg – List names of labels in a document

A deriva­tive of the file lablst.tex (in the LaTeX dis­tri­bu­tion); em­beds it­self in \end{doc­u­ment} and prints, be­low the end of the doc­u­ment it­self, a list of la­bels used.
(Such a pack­age to­day would use \AtEndDoc­u­ment from LaTeX 2e, but this pack­age hacks it­self in with­out cer­e­mony.)