[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 #4 from Jason Merrill <jason at gcc dot gnu.org> ---
I think we want parallel changes for the vec and non-vec cases.

I agree that the diagnostic message needs to be different for C++26, just that
the C++26 diagnostic should also be affected by -Wno-delete-incomplete.

if (complain & tf_error) but permerror_opt returns false, we should not return
error_mark_node.