libstdc++: P2106R0 Alternative wording for GB315 and GB316

libstdc++: P2106R0 Alternative wording for GB315 and GB316

libstdc++-v3/ChangeLog:

	P2106R0 Alternative wording for GB315 and GB316
	* include/bits/ranges_algo.h (in_fun_result): New.
	(for_each_result, for_each_n_result): Change into an alias of
	in_fun_result.
	(in_in_result): New.
	(mismatch_result): Change into an alias of in_in_result.
	(copy_if_result): Change into an alias of in_out_result.
	(swap_ranges_result): Change into an alias of in_in_result.
	(unary_transform_result): Change into an alias of in_out_result.
	(in_in_out_result): New.
	(binary_transform_result): Change into an alias of in_in_out_result.
	(replace_copy_result, replace_copy_if_result, remove_copy_if_result,
	remove_copy_result, unique_copy_result, reverse_copy_result,
	rotate_copy_result, partial_sort_copy_result): Change into an alias of
	in_out_result.
	(in_out_out_result): New.
	(partition_copy_result, merge_result): Change into an alias of
	in_out_out_result.
	(set_union_result, set_intersection_result): Change into an alias of
	in_in_out_result.
	(set_difference_result): Change into an alias of in_out_result.
	(set_symmetric_difference): Change into an alias of in_in_out_result.
	(min_max_result): New.
	(minmax_result, minmax_element_result): Change into an alias of
	min_max_result.
	(in_found_result): New.
	(next_permutation_result, prev_permutation_result): Change into an alias
	of in_found_result.
	(__next_permutation_fn::operator(), __prev_permutation_fn::operator()):
	Adjust following changes to next_permutation_result and
	prev_permutation_result.
	* include/bits/ranges_algobase.h (in_out_result): New.
	(copy_result, move_result, move_backward_result, copy_backward_result,
	copy_n_result): Change into an alias of in_out_result.
	* include/bits/ranges_uninitialized.h (uninitialized_copy_result,
	uninitialized_copy_n_result, uninitialized_move_result,
	uninitialized_move_n_result): Likewise.
	* testsuite/25_algorithms/next_permutation/constrained.cc: Adjust uses of
	structured bindings.
	* testsuite/25_algorithms/prev_permutation/constrained.cc: Likewise.