message: Don't construct face restrictions when there are no face integrators
diff: @@ -51,6 +51,10 @@ PABilinearFormExtension::PABilinearFormExtension(BilinearForm *form)
  localY.UseDevice(true); // ensure 'localY = 0.0' is done on device
  }
  + // Construct face restriction operators only if the bilinear form has
  + // interior or boundary face integrators
  + if (a->GetFBFI()->Size() > 0 || a->GetBFBFI()->Size() > 0)
  + {
  int_face_restrict_lex = trialFes->GetFaceRestriction(
  ElementDofOrdering::LEXICOGRAPHIC, FaceType::Interior);
  if (int_face_restrict_lex)
  @@ -69,6 +73,7 @@ PABilinearFormExtension::PABilinearFormExtension(BilinearForm *form)
  faceBoundY.UseDevice(true); // ensure 'faceBoundY = 0.0' is done on device
  }
  }
  +}
  void PABilinearFormExtension::Assemble()
  {
  