[Bug target/80376] Some vec_xxpermdi usage lead to ICE

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80376

--- Comment #3 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
It's difficult to completely avoid an ICE, as once we have a nested call with
an invalid value it is not simple to recover with our current design.  However,
I will put together a patch that provides better error messages when this
situation arises, and we can consider some re-design work in a later release.