simd_cast: implement more simd_cast_interleaved_argument_order

This is somewhat frustrating: I have to resort to all possible number of
arguments to implement this pattern with variadic templates. The
variants for 10, 12, and 14 arguments to
simd_cast_interleaved_argument_order were missing.

Signed-off-by: Matthias Kretz <kretz@kde.org>
simd_cast: add overload for dropping unnecessary arguments

One specific call to simd_cast<simdarray> would not drop off unnecessary
arguments at the end of the parameter list and thus try to call an
undefined simd_cast<V> overload.
This adds an overload that uses simd_cast_without_last to drop off all
unnecessary arguments at the end.

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