sync with trunk

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@5025 0b2b3880-5936-4365-a048-eb17d2e5a6bf
sync with trunk

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@5026 0b2b3880-5936-4365-a048-eb17d2e5a6bf