Require 'jka-cmpr-hook.

Require 'jka-cmpr-hook.
(jka-compr-info-compress-message, jka-compr-info-compress-program)
(jka-compr-info-compress-args, jka-compr-info-uncompress-message)
(jka-compr-info-uncompress-program, jka-compr-info-uncompress-args)
(jka-compr-info-can-append, jka-compr-info-strip-extension)
(jka-compr-info-file-magic-bytes, jka-compr-get-compression-info)
(jka-compr-info-regexp): Remove.  Provided by jka-cmpr-hook.
(jka-compr-uninstall): Remove entries from
jka-compr-added-to-file-coding-system-alist after they are used.
(jka-compr-error): Remove unused var `curbuf'.
(jka-compr-file-local-copy): Remove unused var `notfound'.