[llvm] [llvm][AArch64] Fix FPDiff rounding direction in non-sibcall tail calls (PR #223545)

[Jon Roelofs via llvm-commits]

jroelofs wrote:

> Failed to cherry-pick: [ec4d25a](https://github.com/llvm/llvm-project/commit/ec4d25ab1d0f47f078fd749f6073f04cc820ddf3)
> 
> https://github.com/llvm/llvm-project/actions/runs/35139098216
> 
> 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/224137

https://github.com/llvm/llvm-project/pull/223545