Fix display of minibuffer prompt in ido.el
* lisp/minibuffer.el (minibuffer--message-overlay-pos): New function. (set-minibuffer-message): Use it to determine where to show the overlay with the temporary message. * lisp/ido.el (ido-exhibit): Revert "Render Ido suggestions using an overlay"; this restores the original code which inserted the match-status information into the minibuffer, instead of displaying it in an overlay with an after-string. Put the special 'minibuffer-message' text property at the beginning of the inserted text. (Bug#39379) * etc/NEWS: * doc/lispref/display.texi (Displaying Messages): * doc/lispref/text.texi (Special Properties): Document the 'minibuffer-message' text property and its effect.