index prefixes don't list all undocumented opcodes

[fghsgh]

It used to be that the only undocumented instruction in the DD/FD blocks were ones which actually contained ixh/ixl/iyh/iyl. However, since the Z180 update, many more of these instructions have been added that do not act any differently to the non-prefixed opcodes (other than taking 4cc longer). However, not all such instructions have been added like this. For example, DD80 is listed as an 8cc add a,b, but DD03 is not listed as a 10cc inc bc.

I think that either all such instructions should be added, or otherwise none of them. Adding all makes it clear how DD actually works. Adding a few but not all implies that all the other ones weren't added for a specific reason.