[llvm] [BOLT][rewrite] warn about functions without CFG before binary analyses. (PR #197294)

[Anatoly Trosinenko via llvm-commits]

https://github.com/atrosinenko commented:

@devnexen Thank you for the patch, I left a few nit-picky comments, but the code change looks good. Could you please add some test cases?

https://github.com/llvm/llvm-project/pull/197294