Support scope extrusion

Not supported in main, might be supported in https://github.com/SkyLabsAI/BRiCk/pull/270.
Example at https://eel.is/c++draft/class.temporary#example-4

```
struct S {
  const int& m;
};
const S& s = S{1};              // both S and int temporaries have lifetime of s         
```