[Bug target/113537] ext should be used more for __builtin_shufflevector

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113537

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
aarch64_vectorize_vec_perm_const does not handle at all the case where the 2
modes are different.