#6529: the checked flag is now part of pers_struct.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@15174 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Synchronize with trunk.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/abstract_intel_emit@15181 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02