also: * removes default constructors from predefined iterators * makes span and string_view views Partially implements P2325. Partially resolves LWG3326. Differential Revision: https://reviews.llvm.org/D102468
sized_range
ranges::size
* adds `sized_range` and conformance tests * moves `disable_sized_range` into namespace `std::ranges` * removes explicit type parameter Implements part of P0896 'The One Ranges Proposal'. Differential Revision: https://reviews.llvm.org/D102434