message: Ensure the method HypreParMatrix::Mult(HypreParVector &,
  HypreParVector &, double, double) can be used when the mfem::Device is
  configured with a backend using a separate memory space, e.g. "cuda".
diff: @@ -1006,6 +1006,8 @@ HypreParMatrix * HypreParMatrix::Transpose() const
  HYPRE_Int HypreParMatrix::Mult(HypreParVector &x, HypreParVector &y,
  double a, double b)
  {
  + x.HostRead();
  + (b == 0.0) ? y.HostWrite() : y.HostReadWrite();
  return hypre_ParCSRMatrixMatvec(a, A, x, b, y);
  }
  