[InstCombine] move shuffle after funnel shift with same-shuffled operands

This extends 432c199e and 9c4770ea with an intrinsic
cited directly in issue #46238

Eventually, we will want to use llvm::isTriviallyVectorizable()
or create some new API for this list, but for now, I am intentionally
making a minimum change to reduce risk and only affect an intrinsic
with regression tests in place.