nir/deref: don't replace casts with deref_struct if we'd lose the stride
The result might be used in a deref_ptr_as_array, which requires a proper stride within lower_explicit_io. If we'd lose that information or end up with a different stride don't execute this optimization.
Closes: #8289 (closed) Signed-off-by: Karol Herbst kherbst@redhat.com