[llvm] [MemProf] Propagate size info used for hint reporting to duplicates (PR #172535)

[Snehasish Kumar via llvm-commits]

snehasish wrote:

> > I'm having trouble connecting the dots between the description and the code changes. From the code I see previously we would have a default initialized value in the map for OldId, now we only update the value if it's found in the `ContextIdToContextSizeInfos` map. Can you elaborate?
> 
> Before we did not propagate this information. Are you looking at where we previously already propagated the ContextIdToAllocationType entry? For the ContextIdToContextSizeInfos propagation I'm only doing it if the OldId existed in the map because this information is optional.

No I just confused myself with the var names `ContextIdToAllocationType` vs `ContextIdToContextSizeInfos`. 

https://github.com/llvm/llvm-project/pull/172535