ENH: lduMatrix: new matrix solvers: PPCG,PPCR

src/OpenFOAM/Make/files

src/OpenFOAM/db/IOstreams/Pstreams/PstreamReduceOps.H

src/OpenFOAM/matrices/lduMatrix/lduMatrix/lduMatrix.H

src/OpenFOAM/matrices/lduMatrix/lduMatrix/lduMatrixATmul.C

...ces/lduMatrix/lduMatrix/lduMatrixUpdateMatrixInterfaces.C

...ces/lduMatrix/smoothers/GaussSeidel/GaussSeidelSmoother.C

...s/nonBlockingGaussSeidel/nonBlockingGaussSeidelSmoother.C

...uMatrix/smoothers/symGaussSeidel/symGaussSeidelSmoother.C

...M/matrices/lduMatrix/solvers/GAMG/GAMGSolverInterpolate.C

src/OpenFOAM/matrices/lduMatrix/solvers/PPCG/PPCG.C

src/OpenFOAM/matrices/lduMatrix/solvers/PPCG/PPCG.H

src/OpenFOAM/matrices/lduMatrix/solvers/PPCR/PPCR.C

src/OpenFOAM/matrices/lduMatrix/solvers/PPCR/PPCR.H

src/Pstream/dummy/UPstream.C

src/Pstream/mpi/PstreamGlobals.C

src/Pstream/mpi/PstreamGlobals.H

src/Pstream/mpi/UPstream.C

src/Pstream/mpi/allReduce.H

src/Pstream/mpi/allReduceTemplates.C

src/finiteArea/faMatrices/faMatrix/faMatrixSolve.C