* lisp/subr.el (point-at-eol, point-at-bol): Make XEmacs compat
aliases obsolete in favor of `pos-bol'/'line-beginning-position' or
'pos-eol'/'line-end-position'.  Update callers.
Ref: https://lists.gnu.org/r/emacs-devel/2022-08/msg00853.html

* lisp/mail/mspools.el (mspools-mode-map):
* lisp/mail/rmailedit.el (rmail-edit-map):
* lisp/mail/rmailsum.el (rmail-summary-edit-map):
* lisp/mail/supercite.el (sc-T-keymap, sc-mode-map)
(sc-electric-mode-map, sc-minibuffer-local-completion-map)
(sc-minibuffer-local-map): Prefer defvar-keymap.

These functions are already autoloaded.
* lisp/mail/mspools.el:
* lisp/progmodes/opascal.el:
* lisp/textmodes/remember.el:
* lisp/woman.el: Remove superfluous installation instructions.

Remove some redundant `:group` args as well.

* lisp/mail/supercite.el: Use lexical-binding.
(completer-disable): Declare var.
(sc-set-variable): Don't rely on dynbind to access `help` variable.

* lisp/mail/mail-extr.el: Use lexical-binding.
(mail-extract-address-components): Avoid use of dynamic scoping to
refer to local vars.

* lisp/mail/mailabbrev.el: Use lexical-binding.
(mail-abbrev-make-syntax-table): Rename `_` variable to `syntax-_`.

* lisp/mail/mailheader.el: Use lexical-binding.
(headers): Don't declare as dynbound globally.
(mail-header-set, mail-header-merge): Declare `headers` as dynbound
locally, instead.  Mark those functions as obsolete.
(mail-header-format): Use `alist-get` instead of `mail-header`.

* lisp/mail/binhex.el (binhex-decode-region-external): Remove always-nil
var `firstline`.

* lisp/mail/emacsbug.el: Use lexical-binding.
(report-emacs-bug): Remove always-nil var `message-end-point`.

* lisp/mail/rmail-spam-filter.el: Use lexical-binding.
(bbdb/mail_auto_create_p): Declare variable.

* lisp/mail/rmail.el (rmail-get-new-mail): Remove always-nil var
`delete-files`.

* lisp/mail/rmailout.el: Use lexical-binding.
(rmail-output-read-file-name): Remove unused var `err`.
(rmail-convert-to-babyl-format): Remove unused var `count`.
(rmail-output-as-mbox): Remove unused vars `from` and `date`.

* lisp/mail/rmailsort.el: Use lexical-binding.
(rmail-sort-messages): Remove unused var `msginfo`.

* lisp/mail/rfc822.el: Use lexical-binding.
* lisp/mail/rmailedit.el: Use lexical-binding.
* lisp/mail/mailclient.el: Use lexical-binding.
* lisp/mail/blessmail.el: Use lexical-binding.
* lisp/mail/mail-hist.el: Use lexical-binding.
* lisp/mail/rmailkwd.el: Use lexical-binding.
* lisp/mail/rmailmsc.el: Use lexical-binding.
* lisp/mail/uce.el: Use lexical-binding.
* lisp/mail/unrmail.el: Use lexical-binding.

Run "TZ=UTC0 admin/update-copyright".

(mspools-mode-map): Remove bindings made redundant by `special-mode-map`.
(mspools-show): Autoload.  Use `erase-buffer`.
(mspools-visit-spool): Use `inhibit-read-only`; simplify a bit.
(mspools-get-spool-files): Avoid `setq`.  Use `pcase-dolist`.
(mspools-revert-buffer): Make (unused) args optional.
(mspools-help, mspools-show-again, mspools-quit): Declare obsolete.