bug#46351: 28.0.50; Add convenient way to bypass Eshell's own pipelining

[Eli Zaretskii]

> From: Sean Whitton <spwhitton@spwhitton.name>
> Cc: michael.albinus@gmx.de, 46351@debbugs.gnu.org
> Date: Wed, 19 Jan 2022 13:39:57 -0700
> 
> >> >   >foo something or other
> >> >
> >> > in Eshell, and have the output of 'something' redirected to 'foo'?  If
> >> > it is possible today, will it be possible after your changes, and what
> >> > will happen with that if 'something' includes the new "*|" pipe
> >> > symbol?
> >>
> >> Interestingly, it's not possible to do that with plain Eshell.  If
> >> someone modifies Eshell's parsing to make it possible, I do not believe
> >> it will interact with em-extpipe.el in any meaningful way.
> >
> > If it doesn't work now, then we cannot break it.
> 
> Okay, so I should add something to skip over my parsing code in the case
> that the first thing in the input is a redirection?

I'm not sure I understand the intent: what do you want to accomplish
by this special handling?