[Bug target/110406] d: Wrong code-gen returning POD structs by value

[ibuclaw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110406

--- Comment #4 from ibuclaw at gcc dot gnu.org ---
It would be good if TYPE_MODE no longer had such a strong influence though.  In
the meantime, I ought to restore behaviour to how it was in 12.x