8068730: Increase the precision of the implementation of java.time.Clock.systemUTC() Summary: Changes the implementation of java.time.Clock.systemUTC() to take advantage of the maximum resolution of the underlying native clock on which System.currentTimeMillis() is based. Reviewed-by: dholmes, rriggs, scolebourne, sla

8071545: Tests are still excluded while the appropriate bug has been fixed Reviewed-by: sspitsyn, sla