Merge from origin/emacs-27

Merge from origin/emacs-27

d66331aea4 (origin/emacs-27) Don't build the Gnulib 'utimens' module ...
f2351a689b Add Harfbuzz dependency
8944310d7c Don't signal during backtrace unrewind (Bug#40088)
8709aaddd8 Fix a couple of problems in changelog generating functions
9ab85f087f Fix cl-concatenate (Bug#40180)
561e9fb91b Improve documentation of project.el commands
b28a9a6cc3 Make svg images with links valid
7515252cce * lisp/tab-line.el (tab-line-new-button-show): New defcustom.

# Conflicts:
#	etc/NEWS
#	nt/gnulib-cfg.mk