[llvm] [AVR] Fix parsing & emitting relative jumps (PR #102936)

[via llvm-commits]

aykevl wrote:

Nevermind, that was a stale build cache (should really fix that some day).

I can confirm that with this fix, all my TinyGo AVR tests start working again on LLVM (when cherry-picking the first commit on top of llvm19-rc3). I'll review the code more in-depth.

https://github.com/llvm/llvm-project/pull/102936