8016117: New sun.misc.FDBigInteger class as part of 7032154 Reviewed-by: martin, iris Contributed-by: Sergey Kuksenko <sergey.kuksenko@oracle.com>, Brian Burkhalter <brian.burkhalter@oracle.com>, Dmitry Nadezhin <dmitry.nadezhin@oracle.com>, Olivier Lagneau <olivier.lagneau@oracle.com>