NYBBLECODES_

The sequence of nybbles, in little-endian order, starting with an extra leading nybble indicating how many nybbles (0-15 of them) are actually unused in the final long. The nybblecodes describe what L1Operation to perform.

If there are no nybblecodes, do not reserve any longs.

To compute the number of valid nybbles, produce zero if there are no longs, otherwise multiply the number of longs by 16, subtract the low nybble of the first long, and subtract one more to account for the space taken by that first nybble.