[InterleaveAccess] Check that binop shuffles have an undef second operand
It is expected that shuffles that we hoist through binops only have a single
vector operand, the other being undef/poison. The checks for
isDeInterleaveMaskOfFactor check that all the elements come from inside the
first vector, but with non-canonical shuffles the second operand could still
have a value. Add a quick check to make sure it is UndefValue as expected, to
make sure we don't run into problems with BinOpShuffles not using BinOps.
Fixes #61749
Differential Revision: https://reviews.llvm.org/D147306