PR c++/64959
	* parser.c (lookup_literal_operator): Return all candidates.
	(cp_parser_userdef_char_literal): Simplify error handling.
	(cp_parser_userdef_numeric_literal):  Pass tf_warning_or_error.
	(cp_parser_userdef_string_literal): Pass tf_warning_or_error.
	Also give higher priority to standard string UDL operator.

From-SVN: r220656