* cp-tree.h (struct saved_scope): Add incomplete field.
        (namespace_scope_incomplete): New macro.
        * decl.c (pushdecl): Use it.
        (hack_incomplete_structures): Use it.  See through artificial
        binding levels.
        (mark_saved_scope): Mark it.

        Implement access control for nested types.
        * search.c (type_access_control): New fn.
        (accessible_p): Now we do perform access control for types.
        * semantics.c (deferred_type_access_control): New fn.
        (initial_deferred_type_access_control): New fn.
        (begin_function_definition): Call it.  Add lookups parm.
        * decl.c (struct binding_level): Add this_class field.
        (pushlevel_class): Set it.
        (mark_binding_level): Mark it.
        (lookup_name_real): Use it.  Call type_access_control.
        (mark_saved_scope): Mark lookups field.
        * cp-tree.h (flagged_type_tree): Add lookups field.
        (struct saved_scope): Add lookups field.
        (type_lookups): New macro.
        * parse.y (declmods): Now <ftype>.
        (parse_decl): Add lookups parm.  Call
        initial_deferred_type_access_control.
        (lang_extdef): Clear type_lookups.
        (typed_declspecs, declmods, typespec): Set lookups field.
        (initdcl): Call deferred_type_access_control.
        (fn.def1, fn.def2, typed_declspecs1, initdcl0_innards, nomods_initdcl0,
        component_decl_1, named_parm): Adjust.
        * friend.c (is_friend): Nested classes are friends of their
        enclosing classes.

        * class.c (currently_open_derived_class): New fn.
        * method.c (hack_identifier): Use it.

        * lex.c (do_identifier): Remove obsolete code.

        * parse.y (typed_typespecs): Propagate new_type_flag properly.

From-SVN: r31837