[Bug c/117164] ICE building gcc.dg/nested-func-12.c with -std=gnu23

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117164

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
For the aggregate return the type of the LHS and the type of the declared
return type have to be compatible according to TYPE_CANONICAL.