[llvm] [BOLT] Update search to proceed upwards from memcpy call (PR #166182)

[Gergely Bálint via llvm-commits]

bgergely0 wrote:

I just skimmed through the original memcpy work to get the context, so bear with me.

Do I understand correctly, that this is only making it faster to find the correct size? Or was the previous way (searching from BB start to the Call) incorrect sometimes?

https://github.com/llvm/llvm-project/pull/166182