Bug 562690 - [1.8][assist] ContentAssist not working on field init with lambda

From https://bugs.eclipse.org/562690:

> Given this class:
```
public class Library {

private Consumer m1 = b -> b./*1*/builder( null );

class RecurseBuilder{
RecurseBuilder builder(Consumer cons) {
Consumer m2 = b -> b./*2*/builder( null );
return this;
}
}
}
```
> Problem at cursor before the comment `/*1*/`, no proposal. But There should be the same as if you put the cursor before `/*2*/` (here it works).