code review request : 7105952: Improve finalisation for FileInputStream/FileOutputStream/RandomAccessFile

[Seán Coffey]

This is a second stab at cleaning up the close() and finalize() methods 
for  FileInputStream / FileOutputStream / RandomAccessFile classes so 
that all parents/referents sharing the same native FileDescriptor are 
closed out correctly.

With Alan's assistance, we have a better implementation in place where 
we avoid the use of counters and instead cycle through a list of shared 
closeables when a FileDescriptor is being shared.

Bug report (not visible yet) http://bugs.sun.com/view_bug.do?bug_id=7105952

webrev : http://cr.openjdk.java.net/~coffeys/webrev.7105952/

regards,
Sean.