bug#24128: 25.1; Strange warning from byte compiler in gud.el and gdb-mi.el

[Eli Zaretskii <eliz@gnu.org>]

When these two files are compiled, the byte compiler emits strange
warnings:

    ELC      progmodes/gdb-mi.elc

  In toplevel form:
  progmodes/gdb-mi.el:675:1:Warning: Unused lexical argument `arg'

    ELC      progmodes/gud.elc

  In toplevel form:
  progmodes/gud.el:735:1:Warning: Unused lexical argument `arg'

But there's no "arg" anywhere in sight on those lines, which are
these:

(defun gdb (command-line)
(defun gud-gdb (command-line)

What is going on here?

In GNU Emacs 25.1.7 (i686-pc-mingw32)
 of 2016-08-01 built on HOME-C4E4A596F7
Repository revision: aa4271ab7299c033760db64bf15476a5e0eee2a5
Windowing system distributor 'Microsoft Corp.', version 5.1.2600
Configured using:
 'configure --prefix=/d/usr --enable-checking=yes,glyphs --with-wide-int
 --with-modules 'CFLAGS=-O0 -gdwarf-4 -g3''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS MODULES

Important settings:
  value of $LANG: ENU
  locale-coding-system: cp1255

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message dired format-spec rfc822 mml
mml-sec password-cache epg epg-config gnus-util mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail
rfc2047 rfc2045 ietf-drums mm-util help-fns help-mode easymenu
cl-loaddefs pcase cl-lib mail-prsvr mail-utils time-date mule-util
tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type
mwheel dos-w32 ls-lisp disp-table w32-win w32-vars term/common-win
tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment
elisp-mode lisp-mode prog-mode register page menu-bar rfn-eshadow timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
frame cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan
thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian
slovak czech european ethiopic indian cyrillic chinese charscript
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote w32notify w32 multi-tty
make-network-process emacs)

Memory information:
((conses 16 93412 6661)
 (symbols 56 20753 0)
 (miscs 48 46 107)
 (strings 16 17771 6169)
 (string-bytes 1 441590)
 (vectors 16 12447)
 (vector-slots 8 432678 5024)
 (floats 8 162 46)
 (intervals 40 262 119)
 (buffers 856 21))