alloc_traits.h (__allow_copy_cons): Remove.
* include/bits/alloc_traits.h (__allow_copy_cons): Remove.
(__check_copy_constructible): Likewise.
* include/bits/unordered_map.h (unordered_map, unordered_multimap):
Do not derive from __check_copy_constructible.
* include/bits/unordered_set.h (unordered_set, unordered_multiset):
Likewise.
* testsuite/23_containers/unordered_map/55043.cc: It is no longer
necessary for is_copy_constructible to be correct to use nested
unordered containers.
* testsuite/23_containers/unordered_multimap/55043.cc: Likewise.
* testsuite/23_containers/unordered_set/55043.cc: Likewise.
* testsuite/23_containers/unordered_multiset/55043.cc: Likewise.
From-SVN: r204790