libstdc++: Remove dg-options "-std=gnu++2a" from constrained algo tests

libstdc++: Remove dg-options "-std=gnu++2a" from constrained algo tests

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/function_objects/range.cmp/equal_to.cc:
	Remove dg-options.
	* testsuite/20_util/function_objects/range.cmp/greater.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/greater_equal.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/less.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/less_equal.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/lwg3530.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/not_equal_to.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/construct_at/1.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/construct_at/92878_92947.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/construct_at/95788.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/destroy/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill/94017.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/94017.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/adjacent_find/constexpr.cc: Likewise.
	* testsuite/25_algorithms/adjacent_find/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/all_of/constexpr.cc: Likewise.
	* testsuite/25_algorithms/all_of/constrained.cc: Likewise.
	* testsuite/25_algorithms/any_of/constexpr.cc: Likewise.
	* testsuite/25_algorithms/any_of/constrained.cc: Likewise.
	* testsuite/25_algorithms/binary_search/constexpr.cc: Likewise.
	* testsuite/25_algorithms/binary_search/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/clamp/constrained.cc: Likewise.
	* testsuite/25_algorithms/constexpr_macro.cc: Likewise.
	* testsuite/25_algorithms/copy/95578.cc: Likewise.
	* testsuite/25_algorithms/copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/copy/debug/constexpr_neg.cc: Likewise.
	* testsuite/25_algorithms/copy_backward/95578.cc: Likewise.
	* testsuite/25_algorithms/copy_backward/constexpr.cc: Likewise.
	* testsuite/25_algorithms/copy_backward/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/copy_backward/debug/constexpr_neg.cc:
	Likewise.
	* testsuite/25_algorithms/copy_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/copy_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/copy_n/constexpr.cc: Likewise.
	* testsuite/25_algorithms/copy_n/constrained.cc: Likewise.
	* testsuite/25_algorithms/count/constexpr.cc: Likewise.
	* testsuite/25_algorithms/count/constrained.cc: Likewise.
	* testsuite/25_algorithms/count_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/count_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/cpp_lib_constexpr.cc: Likewise.
	* testsuite/25_algorithms/equal/95578.cc: Likewise.
	* testsuite/25_algorithms/equal/constexpr.cc: Likewise.
	* testsuite/25_algorithms/equal/constexpr_neg.cc: Likewise.
	* testsuite/25_algorithms/equal/constrained.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/constexpr_neg.cc:
	Likewise.
	* testsuite/25_algorithms/equal_range/constexpr.cc: Likewise.
	* testsuite/25_algorithms/equal_range/constrained.cc: Likewise.
	* testsuite/25_algorithms/fill/94017.cc: Likewise.
	* testsuite/25_algorithms/fill/constexpr.cc: Likewise.
	* testsuite/25_algorithms/fill/constrained.cc: Likewise.
	* testsuite/25_algorithms/fill_n/94017.cc: Likewise.
	* testsuite/25_algorithms/fill_n/constexpr.cc: Likewise.
	* testsuite/25_algorithms/fill_n/constrained.cc: Likewise.
	* testsuite/25_algorithms/find/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find/constrained.cc: Likewise.
	* testsuite/25_algorithms/find_end/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find_end/constrained.cc: Likewise.
	* testsuite/25_algorithms/find_first_of/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find_first_of/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/find_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/find_if_not/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find_if_not/constrained.cc: Likewise.
	* testsuite/25_algorithms/for_each/constexpr.cc: Likewise.
	* testsuite/25_algorithms/for_each/constrained.cc: Likewise.
	* testsuite/25_algorithms/generate/constexpr.cc: Likewise.
	* testsuite/25_algorithms/generate/constrained.cc: Likewise.
	* testsuite/25_algorithms/generate_n/constexpr.cc: Likewise.
	* testsuite/25_algorithms/generate_n/constrained.cc: Likewise.
	* testsuite/25_algorithms/heap/constrained.cc: Likewise.
	* testsuite/25_algorithms/includes/constrained.cc: Likewise.
	* testsuite/25_algorithms/inplace_merge/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/is_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_heap_until/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_partitioned/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_partitioned/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/is_permutation/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_permutation/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/is_sorted/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_sorted/constrained.cc: Likewise.
	* testsuite/25_algorithms/is_sorted_until/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/is_sorted_until/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/iter_swap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/lexicographical_compare/93972.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare/95578.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare_three_way/1.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare_three_way/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/constexpr.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/constrained.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_neg.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_pred_neg.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_valid_range_neg.cc:
	Likewise.
	* testsuite/25_algorithms/make_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/max/constrained.cc: Likewise.
	* testsuite/25_algorithms/max_element/constrained.cc: Likewise.
	* testsuite/25_algorithms/merge/constexpr.cc: Likewise.
	* testsuite/25_algorithms/merge/constrained.cc: Likewise.
	* testsuite/25_algorithms/min/constrained.cc: Likewise.
	* testsuite/25_algorithms/min_element/constrained.cc: Likewise.
	* testsuite/25_algorithms/minmax/constrained.cc: Likewise.
	* testsuite/25_algorithms/minmax_element/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/mismatch/constexpr.cc: Likewise.
	* testsuite/25_algorithms/mismatch/constrained.cc: Likewise.
	* testsuite/25_algorithms/move/93872.cc: Likewise.
	* testsuite/25_algorithms/move/95578.cc: Likewise.
	* testsuite/25_algorithms/move/constexpr.cc: Likewise.
	* testsuite/25_algorithms/move/constrained.cc: Likewise.
	* testsuite/25_algorithms/move_backward/93872.cc: Likewise.
	* testsuite/25_algorithms/move_backward/95578.cc: Likewise.
	* testsuite/25_algorithms/move_backward/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/next_permutation/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/next_permutation/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/none_of/constexpr.cc: Likewise.
	* testsuite/25_algorithms/none_of/constrained.cc: Likewise.
	* testsuite/25_algorithms/nth_element/constexpr.cc: Likewise.
	* testsuite/25_algorithms/nth_element/constrained.cc: Likewise.
	* testsuite/25_algorithms/partial_sort/constexpr.cc: Likewise.
	* testsuite/25_algorithms/partial_sort/constrained.cc: Likewise.
	* testsuite/25_algorithms/partial_sort_copy/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/partial_sort_copy/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/partition/constexpr.cc: Likewise.
	* testsuite/25_algorithms/partition/constrained.cc: Likewise.
	* testsuite/25_algorithms/partition_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/partition_copy/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/partition_point/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/partition_point/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/pop_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/prev_permutation/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/prev_permutation/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/push_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove/constrained.cc: Likewise.
	* testsuite/25_algorithms/remove_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/remove_copy_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove_copy_if/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/remove_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/replace/constrained.cc: Likewise.
	* testsuite/25_algorithms/replace_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/replace_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/replace_copy_if/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/replace_copy_if/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/replace_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/replace_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/reverse/constexpr.cc: Likewise.
	* testsuite/25_algorithms/reverse/constrained.cc: Likewise.
	* testsuite/25_algorithms/reverse_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/reverse_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/rotate/constexpr.cc: Likewise.
	* testsuite/25_algorithms/rotate/constrained.cc: Likewise.
	* testsuite/25_algorithms/rotate_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/rotate_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/sample/constrained.cc: Likewise.
	* testsuite/25_algorithms/search/constexpr.cc: Likewise.
	* testsuite/25_algorithms/search/constrained.cc: Likewise.
	* testsuite/25_algorithms/search_n/97828.cc: Likewise.
	* testsuite/25_algorithms/search_n/constexpr.cc: Likewise.
	* testsuite/25_algorithms/search_n/constrained.cc: Likewise.
	* testsuite/25_algorithms/set_difference/constexpr.cc: Likewise.
	* testsuite/25_algorithms/set_difference/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/set_intersection/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/set_intersection/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/set_symmetric_difference/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/set_symmetric_difference/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/set_union/constexpr.cc: Likewise.
	* testsuite/25_algorithms/set_union/constrained.cc: Likewise.
	* testsuite/25_algorithms/shift_left/1.cc: Likewise.
	* testsuite/25_algorithms/shift_right/1.cc: Likewise.
	* testsuite/25_algorithms/shuffle/constrained.cc: Likewise.
	* testsuite/25_algorithms/sort/constexpr.cc: Likewise.
	* testsuite/25_algorithms/sort/constrained.cc: Likewise.
	* testsuite/25_algorithms/sort_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/stable_partition/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/stable_sort/constrained.cc: Likewise.
	* testsuite/25_algorithms/swap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/swap_ranges/constexpr.cc: Likewise.
	* testsuite/25_algorithms/swap_ranges/constrained.cc: Likewise.
	* testsuite/25_algorithms/transform/constexpr.cc: Likewise.
	* testsuite/25_algorithms/transform/constrained.cc: Likewise.
	* testsuite/25_algorithms/unique/constexpr.cc: Likewise.
	* testsuite/25_algorithms/unique/constrained.cc: Likewise.
	* testsuite/25_algorithms/unique_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/unique_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/constexpr.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/constrained.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_neg.cc:
	Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_pred_neg.cc:
	Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_valid_range_neg.cc:
	Likewise.