c++: Use type_id_in_expr_sentinel in 6 further spots in the parser

c++: Use type_id_in_expr_sentinel in 6 further spots in the parser

The following patch uses type_id_in_expr_sentinel in a few spots which
did it all manually.

2024-12-18  Jakub Jelinek  <jakub@redhat.com>

	* parser.cc (cp_parser_postfix_expression): Use
	type_id_in_expr_sentinel instead of manually saving+setting/restoring
	parser->in_type_id_in_expr_p around cp_parser_type_id calls.
	(cp_parser_has_attribute_expression): Likewise.
	(cp_parser_cast_expression): Likewise.
	(cp_parser_sizeof_operand): Likewise.