[llvm] [SimplifyCFG][Migrated] Transform for redirecting phis between unmergeable BB and SuccBB (PR #67275)

[Omair Javaid via llvm-commits]

omjavaid wrote:

This change breaks LLVM buildbot clang-aarch64-sve-vls-2stage https://lab.llvm.org/buildbot/#/builders/176/builds/5474
I have reverted this patch as the bot has been failing for more than a day without a fix.

https://github.com/llvm/llvm-project/pull/67275