This commit provides a time-effecient LZSA2 decompressor for
the 8088 (and higher) CPU. Decompression speed is roughly 50% faster
than ZX7 on the same hardware.
Because the 8086's BIU is more efficient and can read a word in
a single operation, we can skew LZSA1 decompression faster on 8086
by using a jump table to eliminate 2 comparions.
This commit contributes LZSA1 raw block format decompression code,
optimized for speed for the 8088 and higher processors. With
appropriate compression options (-f1 -m5), decompression speed is
comparable to LZ4.