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

[Patryk Wychowaniec via llvm-commits]

Patryk27 wrote:

Should we force relocations for calls and pc-relative jumps, then? 👀 (cc @aykevl) 

I'm leaning towards resolving the relocations, because the current behavior seems to confuse people:

- https://github.com/llvm/llvm-project/issues/60019
- https://github.com/llvm/llvm-project/issues/104853 (same thing for the riscv backend)

... but I don't have a strong opinion here - linker relaxation seems like a good argument (couldn't llvm just do it on its own, though?) and emiting relocations would certainly allow to remove some pieces of code, so there's pros and cons to both approaches.

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