Merge from origin/emacs-27

3b0938c042 (origin/emacs-27) Render Ido suggestions using an overlay
d5d90dc412 * doc/misc/tramp.texi (Bug Reports): Encourage use of "ema...
ac09e8e121 * lisp/vc/smerge-mode.el (smerge-match-conflict): Fix bug#...
7e37e61f4b Correct statement about ftcr and recommend HarfBuzz
4aec94da37 Avoid leaving artifacts when the system caret is used on w32
5abd8d73b0 Improve display of temporary echo messages

diff --cc doc/lispref/frames.texi
Simple merge

diff --cc doc/misc/tramp.texi
Simple merge

diff --cc src/xdisp.c
Simple merge