[llvm] [AArch64] Reland merge index address with large offset into base address (PR #79951)

[Thurston Dang via llvm-commits]

thurstond wrote:

> hi , thurstond I try to reproduce the issue with your instructions locally, and I don't see obvious build error information, but only get a binary **llvm_build0/bin/llc**. but **llvm_build0/bin/llc -verify-machineinstrs llvm-project/llvm/test/CodeGen/PowerPC/ppc64-nest.ll** doesn't crash on my aarch64 machine. I suspect my local compilation is incomplete for some reason ?
> 
> ```
> ~/source/scratch_dir » find . -name "llc"
> ./llvm_build_ubsan/tools/llc
> ./llvm_build0/bin/llc
> ./llvm_build0/tools/llc
> ------------------------------------------------------------
> ~/source/scratch_dir » ls
> build.log  libcxx_build_ubsan  llvm_build0  llvm_build_ubsan  llvm-project  llvm-zorg
> ```

The failure previously happened in "stage2/ubsan" (https://lab.llvm.org/buildbot/#/builders/85/builds/1102) i.e., using `llvm_build_ubsan/bin/llc`. I don't know why that llc wasn't built. The script is supposed to automatically build it and run the tests.

Are you out of disk space by any chance?

If not, could you please paste all the output from `BUILDBOT_REVISION=43ffe2eed0d9f73789dbe213023733d164999306 llvm-zorg/zorg/buildbot/builders/sanitizers/buildbot_bootstrap_ubsan.sh` into a gist or similar?

https://github.com/llvm/llvm-project/pull/79951