[clang] [clang] Implement lifetime analysis for lifetime_capture_by(X) (PR #115921)

[Boaz Brickner via cfe-commits]

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@@ -1199,6 +1207,21 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
       break;
     }
 
+    case LK_LifetimeCapture: {
+      if (!MTE)
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bricknerb wrote:

Add a comment explaining when do we expect this to happen?

https://github.com/llvm/llvm-project/pull/115921