[llvm] [BOLT][AArch64] Prefer non reloc layout for short branches beyond fragment. (PR #174546)

[Alexandros Lamprineas via llvm-commits]

labrinea wrote:

> Thanks for the patch.
> 
> It will be nice to know more context for this work. I believe the transformation from the description is performed under the `--compact-code-model` flag. We are trying to move away from the legacy `LongJmpPass`.

I have just confirmed this. Thanks @maksfb indeed the code layout looks very similar with compact code model and does not rely on relocations. One option I am seeing is to support the Armv9 compare&branch instructions only in that mode.

https://github.com/llvm/llvm-project/pull/174546