Hi,
The attached patch adjusts vec_perm_const hook to accommodate the new parameter.
For rationale, please see:
https://gcc.gnu.org/pipermail/gcc-patches/2022-May/595128.html

Unfortunately, I am not sure how to cross test this patch.
make all-gcc stage-1 seems to build fine.
Is it OK to commit the patch ?

Thanks,
Prathamesh