[clang] Adding use-after-return in Lifetime Analysis (PR #165370)

[Utkarsh Saxena via cfe-commits]

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@@ -106,6 +120,63 @@ class LifetimeChecker {
                                      /*ConfidenceLevel=*/CurConfidence};
   }
 
+  void checkEscape(const OriginEscapesFact *OEF,
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usx95 wrote:

I think if we correctly use the liveness information, `checkExpiry` can deal with `use-after-return` as well. 
`Liveness` can tell the if origin is live because of an `OriginEscape`, we can mark the loan with a  use-after-return violation.

https://github.com/llvm/llvm-project/pull/165370