[Tarantool-patches] [PATCH v2 01/10] small: sanitized rlist and new region API

[Vladislav Shpilevoy]

This commit, along with the second one, are pushed to
2.4, 2.3 (in addition to master).

Because the first commit contains a bug fix for lsregion.
And the second commit is needed to be able to build the
project with expressions in offsetof and alignof.

Couldn't push it to 1.10, because seems like something
was changed in small, requiring changes in tarantool's
cmake script:
https://github.com/tarantool/tarantool/issues/5060