simdize: support simdize<...bool...>
simdize: support simdize<...bool...>

Uses Vc::Mask<T0> or Vc::simd_mask_array<T0, N> when a bool needs to be
simdized.
+ some documentation of the template parameters to
make_vector_or_simdarray_impl.

Signed-off-by: Matthias Kretz <372ea4eca737a13cd010ee806d4ce7b98ee71550@kde.org>

chr-engwer/Vc,chr-engwer/Vc,VcDevel/Vc,VcDevel/Vc,VcDevel/Vc,chr-engwer/Vc,VcDevel/Vc