Any chance of a `flatten-list' to merge 4 current versions?

[Stephen Eglen]

Hello,
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I'm writing some lisp for another package (ESS) not included in Emacs.
I would like to use a `flatten-list' defun, but was surprised to see
this is not included in elisp.  However, a quick grep of the lisp
directory showed:

% grep -r 'defun .*flatten-list' .
./gnus/message.el:(defun message-flatten-list (list)
./lpr.el:(defun lpr-flatten-list (&rest list)
./lpr.el:(defun lpr-flatten-list-1 (list)
./ps-print.el:(defun ps-flatten-list (&rest list)
./ps-print.el:(defun ps-flatten-list-1 (list)
./eshell/esh-util.el:(defun eshell-flatten-list (args)

i.e. four different packages, all quite widely used, have their own
version.  Would it be worth providing just one common version called
`flatten-list'?

Thanks, Stephen