Stubs for 680x0 programs.

[khval]

If UTF8.library is going to be ported to AmigaOS3.x, then 680x0 programs will expect to be able to use library, currently it will crash and burn, as we have not implemented stubs, to handle the 680x0 register argument passing.

this how a stub should look like:
https://github.com/khval/chipset.library/blob/master/chipset_files/68k_stubs.c

[khval]

Think its best to wait for AmigaOS3.x port, not write stubs first, just in case.