bug#41348: emacs compilation with clang10 fails in the file lib-src/etags.c

[Eli Zaretskii]

> From: Narayanan Nellayi <n.a.narayanan@gmail.com>
> Date: Sun, 17 May 2020 12:32:39 +0530
> Cc: "Narayanan N.A." <n.a.narayanan@gmail.com>
> 
> emacs compilation with clang10 on Ubuntu 20.04 (focal release) fails with an 
> error in the file lib-src/etags.c.
> I am able to fix the issue with a one-line change. This compilation failure 
> is seen on the emacs src from
> top-of-the-master-branch.
> 
> Pls see if this fix is appropriate and consider accordingly.

Does this mean Clang doesn't support __attribute__ ((__fallthrough__))?