[Bug target/92923] __builtin_vec_xor() causes subregs to be used when not using V4SImode vectors

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92923

--- Comment #2 from Peter Bergner <bergner at gcc dot gnu.org> ---
Looking at rs6000-builtin.def, we have the same issue with __builtin_vec_and(),
__builtin_vec_or(), etc., etc.