When clang compiles the following expression:
```c++
return A{B{"Move Ctor"}};
```
(where `B` is a base class for `A`), it adds a call to the move
constructor of `B`. When the code is changed to...
```c++
return A{{"No Move Ctor"}};
```
... a move constructor is invoked neither for `A` nor for `B`.
The lit test demonstrates the difference in the generated AST.
