Rename refactoring does not trigger build

Hi.

Even though the following example is written in Xtend, I'm pretty sure it might be a general Xtext-problem, since I've noticed a similar problem with my own language:

1. Create file Foo.xtend:

package bug
class Foo {
	public String name
}

2. Create file Bar.xtend:

package bug
class Bar {
	def static void main(String[] args) {
		val foo = new Foo
		println(foo.name)		
	}
}

3. Open Xtext Build Console
4. Rename field name to name2 in class Foo. You will notice the Xtext Build Console does not log anything
5. Open Bar.xtend
6. Modify the file in the editor (e.g. insert a line feed somewhere). foo.name2 is now marked with an error marker.