bug#44941: 28.0.50; M-x grep, perhaps all asynch subprocesses

[Drew Adams]

> When I use M-x grep through a lot of files, grep hits appear and
> display all at once.  It used to be that hits in the first files
> searched would appear earlier -- as soon as grep finds them, I expect
> -- but I think Emacs doesn't notice that output from the subprocess any
> more.
> 
> In GNU Emacs 28.0.50

FWIW, I don't see that in Emacs 26.3.  I see the
"used to" behavior of showing hits as `grep' progresses.