Almost every test needed a CanBePiped concept and each implemented it separately, but identically. Consolidate all implementations into test_range.h.
Implemented [[ https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2711r1.html | P2711R1 ]] for existing views. (`join_with_view` is not yet implemented) Reviewed By: #libc, philnik Differential Revision: https://reviews.llvm.org/D144822
std::ranges::drop_while_view
Differential Revision: https://reviews.llvm.org/D135460