`1usize << bits_per_sample` panics when bits_per_sample >= 64.
Use checked_shl to return a LimitsExceeded error instead.
Found by fuzzing decode_comprehensive with a BE TIFF containing
PhotometricInterpretation=RGBPalette and BitsPerSample=83.
Currently, when getting the LZWStatus::NoProgress from the underlying
weezl library, tiff checks that no input bytes were read and no
output bytes were written. Although this is according to what the
weezl library mentions in their doc-comment, it's not what the real
result always looks like.
Our fuzzer found input that triggered exactly this case, where the LZW
reader is able to write some output byte before hitting the NoProgress
status.
This change removes the assert, as the resulting action is anyways to return
an error that can be handled by the caller.
Lilith River