William Astle ('lostwizard') has included an updated patch for gcc6809
in the repository of his lwtools assembler/linker/etc for the 6809
You can grab it from http://snarf.l-w.ca:42042/ (mercurial / hg)
I've posted a guide on my blog about how to go about pulling the bits
and pieces together - see http://boxofdoom.net for more info
- David