[llvm] [llvm-profdata] Reintroduce use of InitLLVM (PR #164736)

[Tim Creech via llvm-commits]

tcreech-intel wrote:

> FWIW we want to support llvm-driver in llvm-profdata, but we first need to replace the use of `cl::opt` with `OptTable`.

Thanks, @petrhosek. I'll clarify the commit message a little to reflect that the current situation is likely temporary.

https://github.com/llvm/llvm-project/pull/164736