decl2.c (add_using_namespace): Iterate over namespaces used indirectly.
* decl2.c (add_using_namespace): Iterate over namespaces used
indirectly.
* decl.c (lookup_name_real): Accept namespace aliases as locals.
(cat_namespace_levels): Ignore aliases.
(duplicate_decls): Ignore duplicate aliases.
* decl2.c (do_namespace_alias): Process block level namespace
aliases. Store alias with pushdecl. Remove odr errors.
* parse.y (namespace_alias): New non-terminal.
(extdef): Use it.