[Bug c/77946] -Wimplicit-fallthrough=1 ICE: tree check: expected tree that contains ‘decl with visibility’ structure, have ‘label_decl’

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77946

--- Comment #7 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #6)
> (In reply to Marek Polacek from comment #4)
> > (In reply to Jakub Jelinek from comment #3)
> > > Thanks.  More reduced (that fails even with -Wimplicit-fallthrough):
> > 
> > Did you mean without?
> 
> No, I meant with, but that it will ICE with any level from 1 to 4 that way.

But only with -O0.