message: Add MFEM_FORALL.
diff: @@ -367,8 +367,7 @@ int ElementRestriction::FillI(SparseMatrix &mat) const
  {
  I[i] = 0;
  }
  - //TODO replace with MFEM_FORALL
  - for (int e = 0; e < ne; e++)
  + MFEM_FORALL(e, ne,
  {
  //TODO use threads here
  for (int i = 0; i < elt_dofs; i++)
  @@ -417,7 +416,7 @@ int ElementRestriction::FillI(SparseMatrix &mat) const
  }
  }
  }
  - }//);
  + });
  auto h_I = mat.HostReadWriteI();
  // We need to sum the entries of I, we do it on CPU as it is very sequential.
  h_I[0] = 0;
  