So filing a QEMU bug on FreeBSD's tracker is supposed to help how?
https://bugs.launchpad.net/qemu/
Since you encountered it and I don't yet have AMD hardware to test, would you mind reporting it?
(1) I do not think it's a QEMU bug. Windows, Linux and older versions of FreeBSD work fine.
(2) I'm one of those people who thought, let's try to compile some software on FreeBSD .. meh can't get it to work.
It's really for FreeBSD to fix this, if they want to on-board new users (and maybe they don't, that's totally fine too).