[clang] [llvm] [Clang-Repl] Add custom function as lambda in launchExecutor and fetch PID of launched executor (PR #147478)

[Abhinav Kumar via llvm-commits]

kr-2003 wrote:

> We will probably need a test in clang/unittest/Interpreter

Ok. So, replicating clang-repl's way of creating interpreter when out-of-process should work, right?

https://github.com/llvm/llvm-project/pull/147478