Moving __cwd from BSS into INITBSS does of course ;-) not only impact the CBM targets but all targets with disk I/O support.
Note: Code using `__cwd-1` may trigger an ld65 range error because __cwd may end up at the very begining of a segment. As far as I see this is an ld65 bug which I'm not try to fix - at least here.
The target 'atarixl' is to be used for Atari XL (and better) machines.
It will disable the OS ROM and enable the Shadow RAM available on
those machine.
Note: This commit is only the inital step towards for this goal that just
replicates the target 'atari' as a starting point!