util/ctags.sh: a script for generating tags file with expanding macros

util/ctags.sh: a script for generating tags file with expanding macros

This script requires Universal Ctags 6.0.0 or newer.

Usage:

	./util/ctags.sh [...options passed to ctags...]

Fixing #10251

Running the script in "tags" make target is suggested by
Dmitry Belyavskiy <beldmit@gmail.com>.

The falling back action for running older ctags if u-ctags 6 is not
available is suggested
by Dr. Matthias St. Pierre <matthias.st.pierre@ncp-e.com>.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20960)