[compiler-rt] [llvm] [Memprof] Adds the option to collect AccessCountHistograms for memprof. (PR #94264)

[Teresa Johnson via llvm-commits]

teresajohnson wrote:

> This patch adds a bunch of 3+ MB binary files to source control. Do you really really need to do that? I'm not sure if there's a specific LLVM policy that forbids it, but it feels like bad practice to me: it's not a very efficient way to use source control and it possibly makes it harderto audit the whole of the LLVM code base.

We need some generally small test binaries for the memprof merging tests, but I see now that they are much larger which is unexpected, and I believe more have been updated than needed. The input executables need to be updated whenever the raw profiles are updated (because their buildids must match), and in this case we have an new field in the raw profile. But I think we should be able to read the old format and leave the existing raw profiles as is - is that correct @mattweingarten ? In that case the old ones don't need to be updated.

But I'm not sure why the size of the executables is so much larger than before, which will also affect the new tests being added. @mattweingarten can you see why, for example, `llvm/test/tools/llvm-profdata/Inputs/buildid.memprofexe` is now 3M larger than before?

https://github.com/llvm/llvm-project/pull/94264