Review request for JDK-8081813: JSONListAdapter should delegate its [[DefaultValue]] to wrapped object

[Attila Szegedi]

Please review JDK-8081813 "JSONListAdapter should delegate its [[DefaultValue]] to wrapped object" for <https://bugs.openjdk.java.net/browse/JDK-8081813> for both 9 and 8u-dev.

webrev for jdk9: <http://cr.openjdk.java.net/~attila/8081813/webrev.jdk9>
webrev for jdk8u-dev: <http://cr.openjdk.java.net/~attila/8081813/webrev.jdk8u-dev>

The change for 9 contains the addition of toNumber() as well, to make it consistent with state already in 8u-dev.
The change for 8u-dev accounts for the lack of getDefaultValue() method on the JSObject interface in 8.

Thanks,
  Attila.