message: Fix intel compiler error
  By using the constructor of std::array to initialize it inside the
  accessors instead of list initialization (which apparently tried to
  convert `std::array<size_type, N>` to `size_type` unsuccessfully).
diff: @@ -266,20 +266,7 @@ protected:
  GKO_ATTRIBUTES constexpr reduced_row_major(gko::dim<dimensionality> size,
  storage_type *storage,
  storage_stride_type stride)
  - : size_{size}, storage_{storage}, stride_{stride}
  - {}
  -
  - /**
  - * Creates the accessor for an already allocated storage space.
  - * It is assumed that all accesses are without padding.
  - *
  - * @param storage pointer to the block of memory containing the storage
  - * @param size multidimensional size of the memory
  - */
  - GKO_ATTRIBUTES constexpr reduced_row_major(dim<dimensionality> size,
  - storage_type *storage)
  - : reduced_row_major{size, storage,
  - helper::compute_stride_array<size_type>(size)}
  + : size_{size}, storage_{storage}, stride_(stride)
  {}
  /**
  @@ -295,14 +282,27 @@ protected:
  GKO_ATTRIBUTES constexpr reduced_row_major(gko::dim<dimensionality> size,
  storage_type *storage,
  Strides &&... strides)
  - : size_{size},
  - storage_{storage},
  - stride_{std::forward<Strides>(strides)...}
  + : reduced_row_major{
  + size, storage,
  + storage_stride_type{{std::forward<Strides>(strides)...}}}
  {
  static_assert(sizeof...(Strides) + 1 == dimensionality,
  "Number of provided Strides must be dimensionality - 1!");
  }
  + /**
  + * Creates the accessor for an already allocated storage space.
  + * It is assumed that all accesses are without padding.
  + *
  + * @param storage pointer to the block of memory containing the storage
  + * @param size multidimensional size of the memory
  + */
  + GKO_ATTRIBUTES constexpr reduced_row_major(dim<dimensionality> size,
  + storage_type *storage)
  + : reduced_row_major{size, storage,
  + helper::compute_stride_array<size_type>(size)}
  + {}
  +
  /**
  * Creates an empty accessor (pointing nowhere with an empty size)
  */
  @@ -595,9 +595,9 @@ protected:
  scalar_stride_type scalar_stride)
  : size_{size},
  storage_{storage},
  - storage_stride_{storage_stride},
  + storage_stride_(storage_stride),
  scalar_{scalar},
  - scalar_stride_{scalar_stride}
  + scalar_stride_(scalar_stride)
  {}
  /**
  @@ -614,12 +614,11 @@ protected:
  GKO_ATTRIBUTES constexpr scaled_reduced_row_major(
  dim<dimensionality> size, storage_type *storage,
  storage_stride_type stride, scalar_type *scalar)
  - : size_{size},
  - storage_{storage},
  - storage_stride_{stride},
  - scalar_{scalar},
  - scalar_stride_{helper::compute_masked_stride_array<
  - size_type, scalar_mask, scalar_stride_dim, dimensionality>(size)}
  + : scaled_reduced_row_major{
  + size, storage, stride, scalar,
  + helper::compute_masked_stride_array<
  + size_type, scalar_mask, scalar_stride_dim, dimensionality>(
  + size)}
  {}
  /**
  