bug#54175: 27.2; Info-follow-reference completions in reverse order

[Howard Melman]

This is the same issue as in bug#38614 which was about
Info-complete-menu-item, but this is about
Info-follow-reference.  I hope it will also be fixed.

Info-follow-reference calls completing-read with a list of
candidates found in the node.  It scans the node from top to
bottom pushing references onto a completions list.  The list
ends up being in the reverse order of position in the node.
For the default completion mechanism this isn't a problem,
but with a completion package like fido or ivy which
immediately displays the list of candidates, this order
isn't particularly useful.

My use case is browsing an info manual, going to a new node
via n, so my point is near the top of the node.  I see I
want to follow the first reference and type f and I'm
presented with a list of completion candidates. The first
candidate is from the bottom of the node, it's not even
visible on my screen.  If the list was in the order as found
in the mode I could just type RET, but now I have to type to
complete or beforehand position point at the reference so
that it will be used as a default.

I suggest adding something like the following in
Info-follow-reference just after the while loop that builds
completions:

     (setq completions (nreverse completions))

I saw this on the macport of Emacs 27.2 but the code on
master looks to me to be the same.

Howard

In GNU Emacs 27.2 (build 1, x86_64-apple-darwin20.6.0, Carbon Version 164 
AppKit 2022.6)
of 2021-11-16 built on Mac-1637103180448.local
System Description:  macOS 11.6.4