We now output "correct" z80 syntax.

Also temp fix on some C programs not compiling...

It seems LLVM sometimes wants to put HL onto the stack, but it first
moves it to IY (seriously wtf) and then tries to move IY to memory
indirectly using the IX register. Originally (and correctly, I
suppose), it would crash here.
However, I'm temporarily allowing it for testing. This isn't an
instruction, and it should't even be using IY for stuff like that
in the first place. LLVM needs to be stopped from getting to this
point.