When we ship LLVM 16, <ranges> won't be considered experimental anymore.
We might as well do this sooner rather than later.
Differential Revision: https://reviews.llvm.org/D132151
All supported compilers that support C++20 now support concepts. So, remove
`_LIB_LIBCPP_HAS_NO_CONCEPTS` in favor of `_LIBCPP_STD_VER > 17`. Similarly in
the tests, remove `// UNSUPPORTED: libcpp-no-concepts`.
Differential Revision: https://reviews.llvm.org/D121528
- Rename test files to follow conventions better
- Split constructor tests that were in a single file
- Add missing tests for take_view and transform_view's default constructors
- Add missing tests for transform_view's view/function constructor
- Fix include guards
- Mark some tests as being specific to libc++
Differential Revision: https://reviews.llvm.org/D108829
Louis Dionne