bug#49734: 28.0.50; define-obsolete-variable-alias

[Devon Sean McCullough]

This change breaks existing libraries.
Better to deprecate old forms for a few years
rather than gratuitously and prematurely sow chaos.

                Peace
                        --Devon

P.S.  Please undo this incompatible change:

--- emacs-27.2/lisp/emacs-lisp/byte-run.el
+++ emacs-28.0.50/lisp/emacs-lisp/byte-run.el
⋮
-(defun make-obsolete-variable (obsolete-name current-name &optional when 
access-type)
+(defun make-obsolete-variable ( obsolete-name current-name when
+                                &optional access-type)

In GNU Emacs 28.0.50 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60 
Version 10.14.6 (Build 18G95))
 of 2021-06-20 built on builder10-14.porkrind.org
Windowing system distributor 'Apple', version 10.3.1671
System Description:  Mac OS X 10.14.6

Configured using:
 'configure --with-ns '--enable-locallisppath=/Library/Application
 Support/Emacs/${version}/site-lisp:/Library/Application
 Support/Emacs/site-lisp' --with-modules'

Configured features:
ACL GMP GNUTLS JSON LIBXML2 MODULES NOTIFY KQUEUE NS PDUMPER THREADS
TOOLKIT_SCROLL_BARS ZLIB

Important settings:
  value of $LANG: en_BE@currency=USD.UTF-8
  locale-coding-system: utf-8-unix

Major mode: ELisp/d

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  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

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny rfc822 mml mml-sec epa
derived epg epg-config gnus-util rmail rmail-loaddefs mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
time-date warnings thingatpt browse-url url url-proxy url-privacy
url-expand url-methods url-history url-cookie url-domsuf url-util
url-parse auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs
password-cache json subr-x map seq gv url-vars mailcap byte-opt compile
text-property-search comint ansi-color ring bytecomp byte-compile cconv
dired-aux cl-loaddefs cl-lib dired dired-loaddefs iso-transl tooltip
eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
term/ns-win ns-win ucs-normalize mule-util term/common-win tool-bar dnd
fontset image regexp-opt fringe tabulated-list replace newcomment
text-mode elisp-mode lisp-mode prog-mode register page tab-bar menu-bar
rfn-eshadow isearch easymenu timer select scroll-bar mouse jit-lock
font-lock syntax font-core term/tty-colors frame minibuffer 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 composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray
cl-preloaded nadvice button loaddefs faces cus-face macroexp files
window text-properties overlay sha1 md5 base64 format env code-pages
mule custom widget hashtable-print-readable backquote threads kqueue
cocoa ns multi-tty make-network-process emacs)

Memory information:
((conses 16 67763 8788)
 (symbols 48 7652 1)
 (strings 32 23129 1733)
 (string-bytes 1 753985)
 (vectors 16 14734)
 (vector-slots 8 197384 12385)
 (floats 8 26 332)
 (intervals 56 398 0)
 (buffers 992 18))