Finalizers are non-canonical

The canonical form of a Java finalizer is:

protected void finalize() throws Throwable()
{
try

{ // ... local code to finalize this class }

catch (Throwable t)
{
}
super.finalize(); // finalize base class.
}

The finalizers in IndexReader, IndexWriter, and FSDirectory don't conform. This
is probably minor or null in effect, but the principle is important.

As a matter of fact FSDirectory.finaliz() is entirely redundant and could be
removed, as it doesn't do anything that RandomAccessFile.finalize would do
automatically.