[clang] [compiler-rt] [llvm] [InstrFDO][TypeProf] Implement binary instrumentation and profile read/write (PR #66825)

[Mingming Liu via cfe-commits]

minglotus-6 wrote:

> My concern with this approach is that compiler-rt is treated as a different project and updating the code within LLVM makes it easy to miss running the test locally for the other project. I think such issues will be caught by the buildbot but having it flagged earlier is better for the developer. What do you think?

Yeah presubmit test coverage makes sense.

If it's desirable to get rid of 'update_vtable_value_prof_inputs.sh' and 'vtable-value-prof-basic.profraw' in the repo, here is another way:
* For LLVM IR tests, store textual profiles in the repo, and run `llvm-profdata merge` to convert it to indexed profiles.
* To have test coverage on raw profiles (generate raw profiles or convert it into other formats), have a compiler-rt test.

I wonder if that is preferred over the current status (with script and `.profraw` in the repo).

https://github.com/llvm/llvm-project/pull/66825