Inferred types for polymorphic functions sometimes produce `Any` instead of type variables

I wanted to play around with the new functionality to insert type signatures. The following:

```haskell
hello = print
```

surprises me, as when I add a type signature with a code action, I get:

```haskell
hello :: GHC.Types.Any -> IO ()
hello = print
```

which is mostly certainly not what I'd expect!