Keep input file in Pparse.Error. Switch it to the new system.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/exception_registration@14108 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Keep input file in Env.Error. Switch it to the new system.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/exception_registration@14109 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02