bug#63253: 29.0.90; with-delayed-message fails in combination with inhibit-message

[Daniel Mendler]

There seems to exist an interaction issue of `with-delayed-message' with
`inhibit-message'. In order to reproduce the issue, start emacs -Q and
evaluate the following function:

(defun delayed-message-bug ()
  (interactive)
  (setq inhibit-message-regexps (list "\\`something"))
  (add-to-list 'set-message-functions #'inhibit-message)
  (while t
    (with-delayed-message (0.5 "Fontifying...")
      (font-lock-flush (point-min) (point-max))
      (font-lock-ensure (point-min) (point-max)))
    (message "Done")))

Then open a large file like emacs/src/xterm.c and run `M-x
delayed-message-bug'. The error may not occur on the first try since it
is timing dependent. Retry a few times if no error is observed. I
observe the internal error

    Error in syntax_table logic for to-the-end intervals

which is produced by `update_syntax_table' from syntax.c.

In GNU Emacs 29.0.90 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.16.0, Xaw scroll bars) of 2023-04-27
Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
System Description: Debian GNU/Linux 11 (bullseye)

Configured using:
 'configure --prefix=/home/user/emacs/install --with-json
 --with-native-compilation --with-x-toolkit=athena --without-dbus
 --without-selinux --without-threads --without-gsettings --with-cairo'

Configured features:
CAIRO FREETYPE GIF GLIB GMP GNUTLS HARFBUZZ JPEG JSON LIBXML2 MODULES
NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 TIFF
TOOLKIT_SCROLL_BARS WEBP X11 XDBE XIM XPM LUCID ZLIB