message: [Slam-only cherry-pick] small update to fix g++ compilation and make the rest of multimat_calculate_ex work
diff: @@ -92,7 +92,7 @@ public:
  * \param subset_idxset a Set of ElementFlatIndex into the SuperMap
  */
  SubMap(SuperMapType* supermap,
  - SubsetType& subset_idxset,
  + SubsetType subset_idxset,
  bool indicesHaveIndirection = true)
  : StridePolicyType(supermap->stride())
  , m_superMap(supermap)
  