* c-decl.c (finish_decl): Set DECL_DEFER_OUTPUT on tentative file-scope
        definitions.
        * toplev.c (rest_of_decl_compilation): Check DECL_DEFER_OUTPUT to
        recognize a tentative definition.  Lose obsolete code.

        * toplev.c (wrapup_global_declarations): Don't emit DECL_COMDAT
        variables unless necessary, either.

From-SVN: r40066