byte0/byte1 lookup incorrect for instructions w/ VEX prefix in decode_fast

The 'interesting' array lookup is using the wrong opcode bytes for instructions w/ VEX prefix. Such instructions imply at least one leading opcode byte dependent on 2-byte or 3-byte VEX prefix and the 'mm' bits in the 2nd byte of the 3-byte VEX prefix.

See decode_fast.c:decode_sizeof.