Implement LWG 2324: Insert iterator constructors should use addressof(). Add two new container classes to the test suite that overload operator &, and add test cases to the insert/front_insert/back_insert iterator tests that use these containers.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@202741 91177308-0d34-0410-b5e6-96231b3b80d8