[llvm] [llvm-profdata][StaticDataLayout] Print summary of data access profiles in llvm-profdata (PR #173087)

[Mingming Liu via llvm-commits]

mingmingl-llvm wrote:

> MemProfSummaryBuilder support is also needed for serializing the summary in v4 and above (see the writer). It's ok to defer this (I see your FIXME in the code), but maybe clarify this in the PR description?

thanks for catching this; and I should also have double check this in cross-reference. Updated the PR description. 

Also tested that the reader `llvm-profdata` works as intended (e.g., in terms of byte-offset) by 'diff' the yaml format. Please take another look, thanks!

```
/path/to/known-good-llvm-profdata show --memory memprof.profdata > prof_baseline.yaml
/path/to/llvm-profdata-with-this-patch show --memory memprof.profdata > prof_new.yaml

diff prof_baseline.yaml prof_new.yaml
```

https://github.com/llvm/llvm-project/pull/173087