bug#58516: 28.1; add option/key to rerun current diff without whitespace changes

[Juri Linkov]

> +(defun diff-ignore-whitespace-all-hunks ()
> +  "Re-diff all the hunks, ignoring whitespace-differences."
> +  (interactive)
> +  (diff--iterate-hunks (point-max) (lambda (_ _)
> +                                     (diff-refresh-hunk t))
> +                       (point-min)))

A question about performance: would this run the diff command
for every hunk?