[compiler-rt] [CopyProf] Implement minimal CopyProf runtime. (PR #223458)

[via llvm-commits]

newgre wrote:

> Could you please add links to the RFC or other relevant patches in the description?

I've updated the description.

> Also, I'm wondering why this needs to be a standalone tool rather than part of memprof.
See RFC for more detail, but the short answer is that the runtime as well as the instrumentation are substantially different compared to what memprof already has.


https://github.com/llvm/llvm-project/pull/223458