re PR c++/30818 (templates and typedefs cause function prototype not to match)
cp/
PR c++/30818
* typeck.c (structural_comptypes): No need to check
resolve_typename_type return value here.
* cp-tree.h (TYPENAME_IS_RESOLVING_P): New.
* pt.c (resolve_typename_type): Follow typename typedefs. Return
original type rather than error_mark_node in case of failure.
* parser.c (cp_parser_nested_name_specifier_opt): Adjust
resolve_typename_type result check.
(cp_parser_direct_declarator, cp_parser_head,
cp_parser_constructor_declarator_p): Likewise.