PR c++/20905
	* parser.c (cp_parser_type_specifier_seq): Add is_condition
	parameter.
	(cp_parser_new_type_id): Pass it.
	(cp_parser_condition): Likewise.
	(cp_parser_conversion_type_id): Likewise.
	(cp_parser_type_id): Likewise.
	(cp_parser_type_specifier_seq): In a condition, do not allow
	invalid type-specifier combinations.
	(cp_parser_exception_declaration): Adjust call to
	cp_parser_type_specifier_seq.

	PR c++/20905
	* g++.dg/parse/cond2.C: New test.

From-SVN: r97857