In the previous code, if the game attempted to seek beyond the track
length, or if a "seek & read" would add up to going beyond the
end-of-the-track, the code would pass those requests to the underlying
codecs to handle (and reject with a corresponding error code).
This PR moves those checks up into the CDROM CD-DA code, and will
short-circuit them. Illegal seeks won't be attempted, however the usual
negative return code will still be passed to the game just like before.
Likewise, reads beyond the end will be pruned so they will get as much
audio as possible, without asking the codec for extra.
e8ac2d60f3
