Several typedefs in [ranges.syn] are not in the library index

* `iterator_t`
* `sentinel_t`
* `const_iterator_t`
* `const_sentinel_t`
* `range_difference_t`
* `range_size_t`
* `range_value_t`
* `range_reference_t`
* `range_const_reference_t`
* `range_rvalue_reference_t`
* `range_common_reference_t`
* `borrowed_iterator_t`
* `borrowed_subrange_t`
* `istream_view`
* `wistream_view`