[llvm] [AVR][MC] Fix incorrect range of relative jumps (PR #109124)

[via llvm-commits]

llvmbot wrote:

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Failed to cherry-pick: efcf52b4e48e9826857747cd8a670ea0f2f23abf

https://github.com/llvm/llvm-project/actions/runs/11563217310

Please manually backport the fix and push it to your github fork.  Once this is done, please create a [pull request](https://github.com/llvm/llvm-project/compare)

https://github.com/llvm/llvm-project/pull/109124