[clang] [analyzer] Discard non-live source frames from the current stack (PR #213779)

[via cfe-commits]

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@@ -52,7 +52,17 @@ static bool isDanglingStackSource(const MemRegion *Source,
         })) {
       return false;
     }
-
+    // Only a source whose frame is still live on the current stack can
+    // dangle. If that frame is not on the stack then the source outlives
+    // the returned value. The source is still alive when the returned value
+    // is used, so it does not dangle.
+    /*
+    if (llvm::any_of(C.stackframes(), [&](const StackFrame &Frame) {
+          if (&Frame != SF)
+            return false;
+          return true;
----------------
isuckatcs wrote:

Nit
```suggestion
          return &Frame == SF;
```

https://github.com/llvm/llvm-project/pull/213779