Add Collections.synchronizedList to classpath

I was trying to get junit to work in avian.  Sadly there is a LOT that was missing (I am going to try a different strategy towards getting junit tests running under avian).

This is just a small piece of commonly used functionality that was missing, and I thought I would provide a pull request for.
This was a bug fix, we should be synchronizing the collection, never a new object.  Otherwise the iterator behavior wont be as expected.