[clang] [clang-repl]: Print stack-trace on crash (PR #117896)

[Mészáros Gergely via cfe-commits]

Maetveis wrote:

> LGTM! Do you have commit access or shall I land this change for you?

Thanks that was extremely quick. I have access, but I'll wait for the CI to finish to be sure. 

https://github.com/llvm/llvm-project/pull/117896