Enable fuzzy matching of operand sizes
This allows automatic fuzzy matching of operand sizes. If an operand
size is not specified, but there is exactly one possible size for the
instruction, select that instruction size. This requires a second
pass through the instruction patterns, and so is slightly slower, but
should be a lot easier to get right than the S- flags, and works even
when there is more than one instruction.
The new SX (Size eXact) flag can be used to prevent fuzzy matching
completely.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>