[Bug c++/119319] [14/15 Regression] incorrect error: invalid use of incomplete type

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119319

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 60788
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=60788&action=edit
Reduced further