bug#15055: shuf --all-permutations

[jidanni]

(info "(coreutils) shuf invocation") says

   These examples all have four input lines, so `shuf' might produce any
   of the twenty-four possible permutations of the input.  In general, if
   there are N input lines, there are N! (i.e., N factorial, or N * (N -
   1) * ... * 1) possible output permutations.

Please add an option to produce all permutations.

Perhaps separated by blank lines or a --separator=...