libstdc++: Fix LWG issues 3389 and 3390

libstdc++: Fix LWG issues 3389 and 3390

libstdc++-v3/ChangeLog:

	LWG 3389 and LWG 3390
	* include/bits/stl_iterator.h (move_move_iterator): Use std::move when
	constructing the move_iterator with __i.
	(counted_iterator::counted_iterator): Use std::move when initializing
	M_current with __i.
	* testsuite/24_iterators/counted_iterator/lwg3389.cc: New test.
	* testsuite/24_iterators/move_iterator/lwg3390.cc: New test.