Port MathFunctions.h to AVX (and possibly other architectures)

Submitted by Christoph Hertzberg @chhtz

Assigned to Nobody

Link to original bugzilla bug (#895)
Version: 3.3 (current stable)
Platform: x86 - AVX

Description

With some effort, we can make the current implementation more generic and avoid code duplication by sharing it for all feasible architectures. Maybe even for HalfPackets and Packets (relevant especially for AVX).

I guess overall this is easy enough to be implemented for 3.3

Blocking

#558 (closed)