[llvm] [AVR] Fix parsing & emitting relative jumps (PR #106722)

[Nico Weber via llvm-commits]

nico wrote:

Looks like this broke check-lld: http://45.33.8.238/macm1/91316/summary.html

Please take a look and revert for now if it takes a while to fix 

https://github.com/llvm/llvm-project/pull/106722