[clang] [clang] Diagnose dangling issues for the "Container<GSLPointer>" case. (PR #107213)

[Utkarsh Saxena via cfe-commits]

================
@@ -525,3 +544,31 @@ void test() {
   std::string_view svjkk1 = ReturnStringView(StrCat("bar", "x")); // expected-warning {{object backing the pointer will be destroyed at the end of the full-expression}}
 }
 } // namespace GH100549
+
+namespace GH100526 {
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usx95 wrote:

Can you also add a use-after-return case:

```cpp
std::optional<std::string_view> uar() {
  std::string s;
  return s;
}
```

https://github.com/llvm/llvm-project/pull/107213