fix interleavedmemory and AsArg usage

With the change of IndexType to simdarray<int, Size> several follow-up
changes are required. Now internal_data needs to be used to access index
data, which in turn requires SuccessiveEntries to provide an
internal_data function.

Signed-off-by: Matthias Kretz <kretz@kde.org>
scalaraccess test: remove unused typedefs

Signed-off-by: Matthias Kretz <kretz@kde.org>
simd_cast: fix alignr call to use the right argument types

arguments must be __m128i. cast.

Signed-off-by: Matthias Kretz <kretz@kde.org>