[clang] [clang-repl] Simplify the value printing logic to enable out-of-process. (PR #107737)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman approved this pull request.

In general, I like the direction this is heading! I found a few nits, but nothing significant jumped out at me.

Approving because I'm going to be out the next few weeks and I didn't want you to feel held up on my sign-off.

https://github.com/llvm/llvm-project/pull/107737