message: revert bilinearform_ext
diff: @@ -125,11 +125,6 @@ void MFBilinearFormExtension::FormLinearSystem(const Array<int> &ess_tdof_list,
  void MFBilinearFormExtension::Mult(const Vector &x, Vector &y) const
  {
  -
  - MFEM_VERIFY(a->GetFBFI()->Size() == 0,
  - "the case of interior face integrators is not"
  - " implemented");
  -
  Array<BilinearFormIntegrator*> &integrators = *a->GetDBFI();
  const int iSz = integrators.Size();
  @@ -188,10 +183,6 @@ void MFBilinearFormExtension::Mult(const Vector &x, Vector &y) const
  void MFBilinearFormExtension::MultTranspose(const Vector &x, Vector &y) const
  {
  - MFEM_VERIFY(a->GetFBFI()->Size() == 0,
  - "the case of interior face integrators is not"
  - " implemented");
  -
  Array<BilinearFormIntegrator*> &integrators = *a->GetDBFI();
  const int iSz = integrators.Size();
  if (elem_restrict)
  