Make change requested in 2023/11/09 LEWG poll: "Modify P2642R4 (Padded mdspan layouts) by removing the feature test macro and bumping the __cpp_lib_submdspan macro...."
Remove "rebase on top of P2630R3" wording, since P2630 has been merged into the current C++ Working Draft. Update current C++ Working Draft reference to the latest at the time of publication, which is N4964.
Update non-wording text and implementation experience.
I've submitted this already as P2642R5.
Make change requested in 2023/11/09 LEWG poll: "Modify P2642R4 (Padded mdspan layouts) by removing the feature test macro and bumping the
__cpp_lib_submdspanmacro...."Remove "rebase on top of P2630R3" wording, since P2630 has been merged into the current C++ Working Draft. Update current C++ Working Draft reference to the latest at the time of publication, which is N4964.
Update non-wording text and implementation experience.