PR libstdc++/79195
	* include/experimental/array (__make_array_elem): New class template
	and partial specialization.
	(__is_reference_wrapper): Move into __make_array_elem specialization.
	(make_array): Use __make_array_elem to determine element type and move
	static assertion into specialization. Qualify std::forward call.
	(to_array): Add exception specifiation.
	* testsuite/experimental/array/make_array.cc: Test argument types
	without a common type.
	* testsuite/experimental/array/neg.cc: Adjust expected error message.

From-SVN: r244813