impossible validation case in specification of floor0
(I'm not sure if this is the right component to assign specification bugs to, but there is no separate component for them.)
Section 6.2.1, floor header decode, says:
7) if any of [floor0_order], [floor0_rate], [floor0_bark_map_size], [floor0_amplitude_bits], [floor0_amplitude_offset] or [floor0_number_of_books] are less than zero, the stream is not decodable
This is not meaningful; all the variables listed above are indicated in the previous lines to be read as unsigned values from the stream, so they couldn't possibly be less than 0.