As it is no longer used.

The current code works with GCC 7 and later.

doesn't work up through NVCC 12

Crashes with internal compiler error. Tested 11.2, 11.4, 11.6 with gcc
9/10

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/mdspan.hpp:
In member function 'virtual void
TestMdspanCTAD_extents_pack_Test::TestBody()':
/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/mdspan.hpp:78:25:
internal compiler error: in tsubst, at cp/pt.c:14560
   78 |   MDSPAN_INLINE_FUNCTION static constexpr size_t rank() noexcept
{ return extents_type::rank(); }