Prefer `declare` over a `put` of `list-indent-function`.

Prefer `declare` over a `put` of `list-indent-function`.

While at it, I enabled lexical-binding in the affected files.

* lisp/cedet/semantic/sb.el: Enable lexical-binding.
(semantic-sb-with-tag-buffer): Use `declare`.

* lisp/cedet/semantic/bovine/el.el: Enable lexical-binding.
(semantic-elisp-setup-form-parser): Use `declare`.

* lisp/emacs-lisp/ert.el:
* lisp/emacs-lisp/ert-x.el: Remove redundant `put`.

* lisp/emulation/cua-rect.el: Enable lexical-binding.
(cua--rectangle-operation, cua--rectangle-aux-replace): Use `declare`.

* lisp/mh-e/mh-acros.el: Enable lexical-binding.
(mh-do-in-gnu-emacs, mh-do-in-xemacs, mh-funcall-if-exists, defun-mh)
(defmacro-mh, with-mh-folder-updating, mh-in-show-buffer)
(mh-do-at-event-location, mh-iterate-on-messages-in-region)
(mh-iterate-on-range): Use `declare`.

* lisp/mh-e/mh-compat.el: Enable lexical-binding.
(mh-flet): Use `declare`.

* lisp/mh-e/mh-e.el: Enable lexical-binding.
(defgroup-mh, defcustom-mh, defface-mh): Use `declare`.

* lisp/net/sieve.el: Enable lexical-binding.  Remove redundant :group args.
(sieve-activate, sieve-remove, sieve-edit-script): Remove unused arg
from the interactive spec.
(sieve-deactivate-all): Remove unused var `name`.
(sieve-change-region): Use `declare`.

* lisp/obsolete/fast-lock.el: Enable lexical-binding.
Remove redundant :group args.  Remove XEmacs compat code.
(save-buffer-state): Remove macro.
(fast-lock-add-properties): Use `with-silent-modifications` instead.

* lisp/obsolete/lazy-lock.el: Enable lexical-binding.
Remove redundant :group args.
(do-while): Use `declare`.
(save-buffer-state): Remove macro.
(lazy-lock-fontify-rest-after-change, lazy-lock-defer-line-after-change)
(lazy-lock-defer-rest-after-change, lazy-lock-after-fontify-buffer)
(lazy-lock-after-unfontify-buffer, lazy-lock-fontify-region):
Use `with-silent-modifications` instead.

* lisp/obsolete/pgg.el: Enable lexical-binding.  Remove XEmacs compat code.
(pgg-save-coding-system, pgg-as-lbt, pgg-process-when-success):
Use `declare`.
(pgg-add-passphrase-to-cache): Remove unused var `new-timer`.
(pgg-decrypt-region): Remove unused var `buf`.

* lisp/org/org-agenda.el (org-let, org-let2): Move from org-macs and
use `declare`.

* lisp/org/org-macs.el (org-let, org-let2): Move these functions that
are inherently harmful to your karma to the only package that uses them.
(org-scroll): Use `pcase` to avoid `eval` and use more readable syntax
for those integers standing for events.

* lisp/progmodes/antlr-mode.el: Enable lexical-binding.
(save-buffer-state-x): Use `declare` and `with-silent-modifications`.

* lisp/international/mule-util.el (with-coding-priority):
* lisp/cedet/ede/proj-comp.el (proj-comp-insert-variable-once):
* lisp/org/org-element.el (org-element-map):
* test/lisp/emacs-lisp/bytecomp-tests.el (test-byte-comp-compile-and-load):
* test/lisp/emacs-lisp/generator-tests.el (cps-testcase): Use `declare`.