[llvm] [compiler-rt] [clang] [Profile] Refactor profile correlation. (PR #70856)

[Zequan Wu via llvm-commits]

ZequanWu wrote:

Chatted with @MaskRay offline, we come to an agreement that it's not good to use relying on the bit in __llvm_profile_raw_version to decide whether or not to dump data/name sections at runtime for the reasons mentioned above. Sent a PR: #71996

> Even if we have a way to fix that, we still need the mode bit at llvm-profile merging step to indicate if the raw profile need debug info/binary to correlate. However, we can get ride of the runtime checking __llvm_profile_has_correlation to allow code compiled w/wo debug-info linked together works well.

I take back this word. When we do `llvm-profdata merge`, we use `-debug-info` to provide debug info file for correlation and the same could apply to binary correlation, a different flag. So, we know which correlation mode we are using.

https://github.com/llvm/llvm-project/pull/70856