[llvm] Revert 112e49b38150b8bfdef01434309d1b05204193e4 due to a miscompile (PR #71598)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

I'm not asking you to re-revert this - just wanting to ensure we track this properly for them to be re-committed.

https://github.com/llvm/llvm-project/pull/71598