bug#44128: bug#47800: bug#44128: [feature/native-comp] When invoking a symlink to the 'emacs' binary Emacs fails to start

[Eli Zaretskii <eliz@gnu.org>]

> From: wilde@sha-bang.de
> Cc: dario.gjorgjevski@gmail.com,  psainty@orcon.net.nz,  jonas@bernoul.li,
>   47800@debbugs.gnu.org,  44128@debbugs.gnu.org,  akrl@sdf.org
> Date: Sat, 17 Apr 2021 21:32:23 +0200
> 
> % ls -l `which emacs`
> lrwxrwxrwx 1 wilde wilde 13 Apr 17 21:21 /home/wilde/apps/emacs-native-dev/bin/emacs -> emacs-28.0.50*
> % ls -l `which emacs-28.0.50` 
> -rwxr-xr-x 1 wilde wilde 25866768 Apr 17 21:21 /home/wilde/apps/emacs-native-dev/bin/emacs-28.0.50*
> 
> # The problem:
> 
> % emacs                      
> emacs: /home/wilde/apps/emacs-native-dev/libexec/emacs/28.0.50/x86_64-p/home/wilde/apps/emacs-native-dev/libexec/emacs/28.0.50/x86_64-pc-linux-gnu/../native-lisp/28.0.50-f13b7cda/preloaded/frame-aa2cd9f8-88c2b85c.eln: cannot open shared object file: No such file or directory

There's something here that I'm missing.  The file name it tries is
clearly a result of some invalid concatenation of string, but I don't
quite see how that could happen.

Can you step through the code with GDB?  If yes, I will ask to show
values of some variables, and that will hopefully pinpoint the buggy
code.

Thanks.