message: Delete alias to try to fix bug.
diff: @@ -1499,9 +1499,10 @@ int SparseMatrix::NumNonZeroElems() const
  if ( Finalized() )
  {
  - Memory<int> nnz;
  - nnz.MakeAlias(I, height, 1);
  - return *nnz.Read(MemoryClass::HOST, 1);
  + Memory<int> nnz_mem(I, height, 1);
  + const int nnz = *nnz_mem.Read(MemoryClass::HOST, 1);
  + nnz_mem.Delete();
  + return nnz;
  }
  else
  {
  