Fix arena_get() for (!init_if_missing && refresh_if_missing) case.

Fix arena_get() to refresh the cache as needed in the (!init_if_missing
&& refresh_if_missing) case.

This flaw was introduced by the initial arena_get() implementation,
which was part of 8bb3198f72fc7587dc93527f9f19fb5be52fa553 (Refactor/fix
arenas manipulation.).
1 file changed