[Bug target/92729] [avr] Convert the backend to MODE_CC so it can be kept in future releases

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92729

--- Comment #24 from Richard Biener <rguenth at gcc dot gnu.org> ---
Amending / adjusting
https://gcc.gnu.org/wiki/Building_Cross_Toolchains_with_gcc
(the only place that somewhat "documents" how to setup AVR testing) is
appreciated.