[llvm] [BasicBlockSections] Apply path cloning with -basic-block-sections. (PR #68860)

[Rahman Lavaee via llvm-commits]

rlavaee wrote:

> Do you have some recent perf numbers for this kind of optimization? We've tried something similar internally in the past but didn't see any perf wins; i wonder if it makes sense for us to reconsider the optimization.

We got 2% improvement on clang (over Propeller-optimized). For internal benchmarks, we got 0.4% improvement on Search before, but I will need to refresh that result. The analysis part of this is not released externally though.

https://github.com/llvm/llvm-project/pull/68860