Make macro work in place of anonymous function

The macro should work in the following situation:

```scala
case class A(b: B)
case class B(c: C)
case class C(d: D)
case class D(s: String)

def expectFunction[T](f: A => T): T = ...

expectFunction(?(_.b.c.d.s))
```

Current it works if you do:

```scala
expectFunction(a => ?(a.b.c.d.s))
```

but it would be nice to be able to use the simpler syntax