WIP: Index vectorization

Separating AoSoA indices into two functions

core/src/impl/Cabana_Index.hpp

@@ -47,8 +47,7 @@ class Index
     KOKKOS_FORCEINLINE_FUNCTION
     static constexpr int s( const int particle_index )
     {
-        return (particle_index - (particle_index & array_size_offset)) >>
-            array_size_binary_bits;
+        return (particle_index - (particle_index % array_size)) / array_size;
     }
 
     /*!
@@ -62,7 +61,7 @@ class Index
     KOKKOS_FORCEINLINE_FUNCTION
     static constexpr int i( const int particle_index )
     {
-        return particle_index & array_size_offset;
+        return particle_index % array_size;
     }
 
     /*!