re PR c++/20789 (ICE with incomplete type in template)
cp:
PR c++/20789
* decl.c (cp_finish_decl): Clear runtime runtime initialization if
in-class decl's initializer is bad.
PR c++/21929
* parser.c (struct cp_parser): Document that scope could be
error_mark.
(cp_parser_diagnose_invalid_type_name): Cope with error_mark for
scope.
(cp_parser_nested_name_specifier): Return NULL_TREE on error.
(cp_parser_postfix_expression): Deal with null or error_mark
scope.
(cp_parser_elaborated_type_specifier): Adjust
cp_parser_nested_name_specifier call.