e1e9e8d7aa
My "simplification" of std::compare_three_way's constraints in commit f214ffb336d582a66149068a2a96b7fcf395b5de was incorrect, because std::three_way_comparable_with imposes additional restrictions beyond the <=> expression being valid. * libsupc++/compare (compare_three_way): Fix constraint so that BUILTIN-PTR-THREE-WAY does not require three_way_comparable_with. * testsuite/18_support/comparisons/object/builtin-ptr-three-way.cc: New test.