[clang] [Clang-Repl] Adds custom lambda in launchExecutor and PID retrieval (PR #152562)

[Jordan Rupprecht via cfe-commits]

rupprecht wrote:

Broadly speaking, bazel tests are much more explicit about paths, and you can make few assumptions about where things will be. A common fix is to have paths passed in as flags/env vars, or sometimes you can "copy" files (often just a symlink) so that it will be in the same dir. I think it's fine if we just skip this test for bazel for now.

https://github.com/llvm/llvm-project/pull/152562