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
61ad58f3aa