libarchive: merge vendor bugfixes
Bugfixes:
IS #1685 and OSS-Fuzz #38764 (security): (ISO reader) fix possible heap buffer overflow in read_children() IS #1715 and OSS-Fuzz #46279 (security): (RARv4 reader) fix heap-use-after-free in run_filters()
(cherry picked from commit 9f690fcfdc050f566466ac10cca29ff43bf4fe92)