[clang] [LifetimeSafety] Implement multi-level origins (PR #168344)

[Yitzhak Mandelbaum via cfe-commits]

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@@ -52,41 +62,118 @@ struct Origin {
   }
 };
 
-/// Manages the creation, storage, and retrieval of origins for pointer-like
-/// variables and expressions.
-class OriginManager {
+/// A list of origins representing levels of indirection for pointer-like types.
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ymand wrote:

Do you track through templates, like `std::optional<int*>`?

https://github.com/llvm/llvm-project/pull/168344