[llvm] [MemProf] Fix reporting with -memprof-matching-cold-threshold (PR #173327)

[Teresa Johnson via llvm-commits]

teresajohnson wrote:

> Is it possible to add the allocation type to contexttotalsize struct instead of creating a new pair?

I didn't for a couple reasons. For one, the ContextTotalSize data structure is used other places, such as during the LTO step. And secondly, due to context trimming a summarized context with its allocation type can correspond to multiple context/size pairs. For the Trie during matching, the redundancy (in the new vector of pairs) is ok from a convenience standpoint, but during LTO I don't want to carry around extra memory.

https://github.com/llvm/llvm-project/pull/173327