Improve a bit libarchive's corpus (#8683)
Improve a bit libarchive's corpus (#8683)

- Add corkami's repository of weird formats/archives
- Speed up compilation a bit

Co-authored-by: Julien Voisin <85d099d025d9e75aa56e67c2f64641cdd4f9d106@google.com>
skia-dev/oss-fuzz,skia-dev/oss-fuzz,skia-dev/oss-fuzz,google/oss-fuzz,google/oss-fuzz,google/oss-fuzz,google/oss-fuzz,skia-dev/oss-fuzz,skia-dev/oss-fuzz,google/oss-fuzz,skia-dev/oss-fuzz,google/oss-fuzz,google/oss-fuzz,skia-dev/oss-fuzz,google/oss-fuzz,skia-dev/oss-fuzz,google/oss-fuzz,skia-dev/oss-fuzz,google/oss-fuzz,skia-dev/oss-fuzz,google/oss-fuzz,skia-dev/oss-fuzz