#6411: -static-libgcc by default.

git-svn-id: http://caml.inria.fr/svn/ocaml/version/4.02@15008 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
#6411: background info for -static-libgcc.

git-svn-id: http://caml.inria.fr/svn/ocaml/version/4.02@15009 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02