Add generation of an FD or SFD or an XML from interface and proto files only for OS4

For PPC, especially on OS4, the register assignment is fixed and defined by the ABI. And theoretically you could even parse the interface file, to find out the order, and therefore the LVOs, of all functions. So it possible to create and FD files just from interface and proto file.

That could be handy for example when one have only include and interface files, and want to create link lib.