[llvm] [VPlan] Use BlockFrequencyInfo in getPredBlockCostDivisor (PR #158690)

[Luke Lau via llvm-commits]

lukel97 wrote:

> The PR description still mentions +0.3% compile-time impact, but IIUC with the latest changes it is much lower, right? Would be good to update

Woops, that was missing a zero. Fixed now to 0.03%.

https://github.com/llvm/llvm-project/pull/158690