Merge from origin/emacs-28

08de838531 ; Improve commentary in the last change
3da9fa875b Make hieroglyphs display correctly with existing fonts
928e05f2d6 Clarify "default face attributes" in the ELisp manual
5dbb04e0eb Make `C-u RET' work again
d72fefdeab Fix typos in the manual and in a comment

diff --cc doc/lispintro/emacs-lisp-intro.texi
Simple merge

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

diff --cc lisp/simple.el
Simple merge