tests of F14 in relocatable shared memory

Summary:
F14 maps and sets support fancy pointers and stateful allocators.
This diff includes tests that verify this functionality and show how
boost::interprocess's location-relative pointers can be used to construct
address-independent F14 maps and sets in shared memory segments.

This is a test-only diff.

Reviewed By: shixiao

Differential Revision: D7969966

fbshipit-source-id: 77b3e2705bc7462518246a96b73e0f3f9c542c6a