Request for review & approval - 8067800: Clarify java.time.chrono.Chronology.isLeapYear for out of range years

[Rob McKenna]

Hi folks,

Looking to backport https://bugs.openjdk.java.net/browse/JDK-8067800 to 
JDK8 minus the spec change.

http://cr.openjdk.java.net/~robm/8067800/webrev.01/

Basically we're throwing an unexpected exception when an out-of-range 
year is passed as a parameter despite the spec saying that the parameter 
need not be valid:

http://docs.oracle.com/javase/8/docs/api/java/time/chrono/HijrahChronology.html#isLeapYear-long-

	-Rob