[Bug c++/115747] [C++26] P3144R2 - Deleting a pointer to an incomplete type should be ill-formed

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115747

--- Comment #8 from Jason Merrill <jason at gcc dot gnu.org> ---
> Updated patch.  Had to guard return error_mark_node for the non-SFINAE case
> on !flag_permissive, otherwise it triggers an ICE (statement parsing into
> error_mark_node without seen_error ()).

Hmm, I think checking seen_error() would be better than flag_permissive, to
support -Wno-error=delete-incomplete .  Or even compare errorcount before and
after the permerror_opt.

Perhaps the currently bool diagnostic functions should instead different values
for warning and error...