When there's an error in a SUBROUTINE or FUNCTION statement, errors
cascade quickly because the body of the subprogram or interface isn't in
the right context. So, if a SUBROUTINE or FUNCTION statement is
expected, and contains a SUBROUTINE or FUNCTION keyword, it counts as
one -- retain and emit any errors pertaining to the arguments or suffix,
recover to the end of the line if needed, and proceed.