bug#71163: Cursor can disappear off the window if no-special-glyphs is enabled

[Emre Yolcu <mail@emreyolcu.com>]

If the layout parameter no-special-glyphs is enabled and a line is 
exactly as wide as a window, then the cursor placed at the end of the 
line disappears off the window. Steps to confirm after "emacs -Q":

1. Evaluate the following:

(set-frame-parameter nil 'no-special-glyphs nil)
   (fringe-mode 0)
   (scroll-bar-mode -1)

2. Insert some line that is exactly as wide as the window, leaving the 
cursor at the end of the line.

After those steps, the cursor is not visible. I'm not sure if this is 
the intended behavior. I would expect the cursor to appear at the 
beginning of the next screen line instead. If no-special-glyphs is not 
enabled, then, as expected, the final character of the first screen line 
is displayed as the continuation indicator "\", and the actual final 
character of the line appears on the next screen line, with the cursor 
after it.

I have confirmed this behavior with Emacs 29.3 on macOS and Windows.