This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
This updates gnulib to a relatively recent commit. Most of this was
done by the gnulib import script; the only change I made was to
update-gnulib.sh.
Tested on x86-64 Fedora 34. I also did a mingw cross build.
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
