[clang] [analyzer] Modernize, improve and promote chroot checker (PR #117791)

[Balazs Benics via cfe-commits]

steakhal wrote:

Hi Vince, I figured it's easier if I just push to your branch with my recommendations.
Let me know if you like it. Challenge it if not.

https://github.com/llvm/llvm-project/pull/117791