[clang] [REAPPLY][Clang-Repl] Add support for out-of-process execution. #110418 (PR #144064)

[Vassil Vassilev via cfe-commits]

vgvassilev wrote:

Do we have some cache per test suite run to use? Perhaps we can compute that once and store it into a global lit cache and don’t re-evaluate many times?

https://github.com/llvm/llvm-project/pull/144064