Auto merge of rust-lang#53460 - JoshBrudnak:master, r=estebank

Fix compile panic on non existent type return

Reverted the change rust-lang@28a76a9#diff-4ed25c00aceb84666fca639cf8101c7cL1069 which was panicking when returning a type that cannot be found in the current scope and added testing for the compile error.

For example:
```rust
fn addition() -> Wrapper<impl A> {}
```
Where Wrapper is undefined in the scope.

Author: bors