Drop #ifdef since ICC 15 finally understands alignas
Drop #ifdef since ICC 15 finally understands alignas

Drop an #ifdef hack that made the code compile with ICC but removed an
important alignment restriction. The relevant unit test still fails, so
it seems like only the ICC frontend understands alignas.

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

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