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

[Balazs Benics via cfe-commits]

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@@ -1750,6 +1750,21 @@ Critical section handling functions modeled by this checker:
    }
  }
 
+.. _unix-Chroot:
+
+unix.Chroot (C)
+"""""""""""""""""""""
+Check improper use of chroot.
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steakhal wrote:

This documentation should explain how is `chroot` used incorrectly, and why is it a big deal if used incorrectly?
Without explaining this even if we report this the users wouldn't know how to fix this issue.

I don't really know this checker, but I'm sure it also has some limitations that we could disclose here.

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