Partial implementation of C++20 of <ranges> header
* doc/doxygen/user.cfg.in: Add new header.
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/precompiled/stdc++.h: Include new header.
* include/std/ranges: New header.
(ranges::sentinel_t, ranges::range_value_t, ranges::range_reference_t)
(ranges::range_rvalue_reference_t, ranges::sized_range)
(ranges::output_range, ranges::input_ranges, ranges::forward_range)
(ranges::bidirectional_range, ranges::random_access_range)
(ranges::contiguous_range, ranges::common::range): Define.
* testsuite/24_iterators/headers/iterator/synopsis_c++20.cc: Check
that disabled_sized_sentinel can be specialized.
* testsuite/std/ranges/access/begin.cc: Include <ranges> instead of
<iterator>.
* testsuite/std/ranges/access/cbegin.cc: Likewise.
* testsuite/std/ranges/access/cdata.cc: Likewise.
* testsuite/std/ranges/access/cend.cc: Likewise.
* testsuite/std/ranges/access/crbegin.cc: Likewise.
* testsuite/std/ranges/access/crend.cc: Likewise.
* testsuite/std/ranges/access/data.cc: Likewise.
* testsuite/std/ranges/access/empty.cc: Likewise.
* testsuite/std/ranges/access/end.cc: Likewise.
* testsuite/std/ranges/access/end_neg.cc: Likewise.
* testsuite/std/ranges/access/rbegin.cc: Likewise.
* testsuite/std/ranges/access/rend.cc: Likewise.
* testsuite/std/ranges/access/size.cc: Likewise.
* testsuite/std/ranges/access/size_neg.cc: Likewise.
* testsuite/std/ranges/headers/ranges/synopsis.cc: New test.
* testsuite/std/ranges/range.cc: New test.
* testsuite/std/ranges/refinements.cc: New test.
* testsuite/std/ranges/sized.cc: New test.
* testsuite/util/testsuite_iterators.h: Add aliases for range types.
(output_iterator_wrapper::WritableObject::operator=): Add const
qualifier so that output_iterator_wrapper satisfies writable.
From-SVN: r277697
328b52d675