Fix Out_of_memory/Stack_overflow.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/raise_variants@14237 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Revert bad(?) commit.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/raise_variants@14238 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02