tests: check for MaskType/mask_type

refs #661

Signed-off-by: Matthias Kretz <kretz@kde.org>
tests: check IndexType to be simd_array<int, Size>

refs #661

Signed-off-by: Matthias Kretz <kretz@kde.org>
simdarray: remove underscore in class name

refs #611

Signed-off-by: Matthias Kretz <kretz@kde.org>
tests: test simd_cast from simd_mask_array

Signed-off-by: Matthias Kretz <kretz@kde.org>
Scalar: several simd_casts to Scalar Mask/Vector

Signed-off-by: Matthias Kretz <kretz@kde.org>
cast test: don't repeat test mask

use different masks when using multiple arguments to simd_cast for more
thorough testing of correctness

Signed-off-by: Matthias Kretz <kretz@kde.org>
convert utils test to new API

Signed-off-by: Matthias Kretz <kretz@kde.org>
new function interleave(V, V)

The function returns a pair of V, V where the low/high entries of the
input vector entries are reordered to: a0, b0, a1, b1, ...

with unit test in utils.cpp

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