The compiler doesn't understand type parameters in @:overload

Revision: 0fc630d

``` haxe

var op:Operation = null;
op.run(function(c) c.next()); // Failed with: Operation.T has no field next

typedef Operation = {
@:overload(function(cb:T->Void):Void {})
function run():Void;
}
typedef Cursor = {
function next():Void;
}
```

The above code will fail to compile.

Changing `Operation` to the following will make it go through:

``` haxe
typedef Operation = {
@:overload(function():Void {})
function run(cb:T->Void):Void;
}
```