bug#45533: 28.0.50; font-lock-variable-name-face regression

[Andreas Röhler]

Looks like fixing bug#45341 introduced a regression WRT bug#44568: font 
lock of assignments with type hints

Load the code below or see  "var3: Mapping" in center of attached png

---

# from typing import Mapping, Tuple, Sequence
var1: int = 5
var2: Mapping[int, int] = {10: 1024}
var3: Mapping[Tuple[int, int], int] = {(2, 5): 32}
var4: Sequence[Sequence[int]] = [[1], [1, 2], [1, 2, 3]]
var5: Sequence[Mapping[str, Sequence[str]]] = [
    {
    'red': ['scarlet', 'vermilion', 'ruby'],
    'green': ['emerald', 'aqua']
    },
    {
    'sword': ['cutlass', 'rapier']
    }
]

[a, b, c] = 1, 2, 3
a, *b, c = range(10)
inst.a, inst.b, inst.c = 'foo', 'bar', 'baz'
(a, b, *c, d) = x, *y = 5, 6, 7, 8, 9

---


In GNU Emacs 28.0.50 (build 1, i686-pc-linux-gnu, GTK+ Version 3.14.5, 
cairo version 1.14.0)
 of 2020-12-27
Repository revision: df882c9701755e2ae063f05d3381de14ae09951e
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.11604000
System Description: Debian GNU/Linux 8 (jessie)

Configured using:
 'configure --with-mailutils -with-modules --with-ffi'

Configured features:
XPM JPEG TIFF GIF PNG CAIRO SOUND DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL
GNUTLS LIBXML2 FREETYPE LIBOTF ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE
XIM MODULES THREADS PDUMPER

Important settings:
  value of $LANG: de_DE.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Python

Minor modes in effect:
  shell-dirtrack-mode: t
  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 pp wid-edit descr-text help-mode emacsbug message
rmc puny dired dired-loaddefs rfc822 mml mml-sec epa derived epg
epg-config gnus-util rmail rmail-loaddefs text-property-search mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils vc-git
diff-mode easy-mmode python easymenu tramp-sh tramp tramp-loaddefs
trampver tramp-integration files-x tramp-compat shell pcomplete
parse-time iso8601 time-date ls-lisp format-spec auth-source cl-seq
eieio eieio-core cl-macs eieio-loaddefs password-cache json subr-x map
seq byte-opt gv bytecomp byte-compile cconv comint ring cl-loaddefs
cl-lib ansi-color iso-transl tooltip eldoc electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd
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 timer select scroll-bar mouse
jit-lock font-lock syntax facemenu 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 dbusbind inotify dynamic-setting system-font-setting
font-render-setting cairo move-toolbar gtk x-toolkit x multi-tty
make-network-process emacs)

Memory information:
((conses 8 172703 19174)
 (symbols 24 45243 1)
 (strings 16 133078 2687)
 (string-bytes 1 2663814)
 (vectors 8 17215)
 (vector-slots 4 625868 73776)
 (floats 8 48 35)
 (intervals 28 526 70)
 (buffers 560 12)
 (heap 1024 17094 3579))

pythen-el.png
Description: PNG image