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

[via llvm-commits]

vfdff wrote:

Yes, thank you very much for helping.  I add the commit 46ea6571 to fix a build crash, and this also fix a runtime issue for spec2017 with LTO enable after your bug report.

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