Clang used to support [[nodebug]] everywhere except on typedefs. Since
we don't support such old Clangs anymore, we can get rid of _LIBCPP_NODEBUG_TYPE
in favour of always using _LIBCPP_NODEBUG.
Differential Revision: https://reviews.llvm.org/D108996
Moves:
* `std::move`, `std::forward`, `std::declval`, and `std::swap` into
`__utility/${FUNCTION_NAME}`.
* `std::swap_ranges` and `std::iter_swap` into
`__algorithm/${FUNCTION_NAME}`
Differential Revision: https://reviews.llvm.org/D103734