These patches come from

  http://lists.gnu.org/archive/html/emacs-devel/2016-11/msg00520.html

There are two patches to fix some deficiencies in
comint-insert-previous-argument:

1. a prefix argument to comint-insert-previous-argument inserts the
INDEX-th argument, not just the last one. bash counts from the beginning
of the argument list, but zsh counts from the end. A new variable is
added to allow the user to choose the zsh behavior

2. comint-insert-previous-argument had logic to find trailing &, which
was buggy and got confused if && was encountered. This logic is not
present in bash or zsh, so it was removed, and the bug went away with
it.