<xutility>: ranges::iter_swap is broken

[statementreply]

Describe the bug

STL/stl/inc/xutility

Lines 1069 to 1071 in c10ae01

	} else if constexpr (_Choice<_Ty1, _Ty2>._Strategy == _St::_Exchange) {
	*static_cast<_Ty1&&>(_Val1) =
	_Iter_exchange_move(static_cast<_Ty1&&>(_Val1), static_cast<_Ty2&&>(_Val2));

The behavior of this constexpr branch is incorrect.

STL version

https://github.com/microsoft/STL/commit/c10ae01b4d9508eed9d5f059a120ee7223b6ac12

Additional context

This bug causes test failure in #1062.