Remove AMG code in non-AMG ISTL solvers
The base class for non overlapping ISTL solvers ISTLBackend_NOVLP_BASE_PREC
uses the method createIndexSetAndProjectForAMG
to create a parallel index set for AMG. This line of code dates back to the time where the class ISTLBackend_AMG_NOVLP
did not exist. Nowadays, (I think) support for AMG should not be added to the non-AMG solvers.
This is even necessary when the underlying code does not hold the assumptions that the createIndexSetAndProjectForAMG()
function has:
* \warning This function silenty assumes that the matrix only has a single level
* of blocking and will not work correctly otherwise. Also note that AMG
* will only work correctly for P1 discretisations.