Summary:
This patch changes std::function to use allocator_traits to rebind the allocator instead of allocator itself.
It also changes most of the tests to use `bare_allocator` where possible instead of `test_allocator`.
Reviewers: mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D8391
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@232686 91177308-0d34-0410-b5e6-96231b3b80d8
