sinc with TL

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@5045 0b2b3880-5936-4365-a048-eb17d2e5a6bf
fixed wrong allocations type for the new StructElements and a wrong copy()

git-svn-id: https://foundry.supelec.fr/svn/luatex/branches/experimental@5046 0b2b3880-5936-4365-a048-eb17d2e5a6bf