2019-05-09  François Dumont  <fdumont@gcc.gnu.org>

	* include/bits/stl_deque.h
	(operator==(const _Deque_iterator<>&, const _Deque_iterator<>&)):
	Make hidden friend.
	(operator!=(const _Deque_iterator<>&, const _Deque_iterator<>&)):
	Likewise.
	(operator<(const _Deque_iterator<>&, const _Deque_iterator<>&)):
	Likewise.
	(operator<=(const _Deque_iterator<>&, const _Deque_iterator<>&)):
	Likewise.
	(operator>(const _Deque_iterator<>&, const _Deque_iterator<>&)):
	Likewise.
	(operator>=(const _Deque_iterator<>&, const _Deque_iterator<>&)):
	Likewise.
	(_Deque_iterator<>::operator+(difference_type)): Likewise and allow NRVO
	copy elision.
	(_Deque_iterator<>::operator-(difference_type)): Likewise.

From-SVN: r271027