Backport of a fix in vtkOverlappingCellsDetector to PV 9.1
The all_to_all communication in this method is unnecessary because when the link map is being generated, it should be symmetric by construction, so all the information is already present.
The signature of the method is also changed. It now uses polymorphism
when possible, and the BlockT
template parameter is not relevant
anymore.
2 versions are written: one taking a std::set as a parameter, and the other taking a std::map<int, DummyT>. This gives a little flexibility on the type of this link map, and allows to use an already initialize map if the user needed to carry extra data when generating the link map.
(cherry picked from commit 8400ec38)