bug#44632: 27.1.50; Left-to-right Arabic shaping breaks at property bounds

[Thamer Mahmoud]

This also affects overlays and `transient-mark-mode' region.

1. Eval:

(with-current-buffer-window "*shaping testcase*" nil nil
  (insert "L2R عربي" "\n\n")
  (insert "عربي")
  (put-text-property 5 6 'face 'highlight)
  (put-text-property 11 12 'face 'highlight))

2. Notice the AIN(ع) in the L2R paragraph has the wrong shape.

--
Regards,
Thamer