[Bug c++/70649] [6 Regression] Incorrect C++ warning on zero-sized array passing

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70649

--- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> ---
Created attachment 38272
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38272&action=edit
fix