[8u20] approval request for 8044000: Access to undefined property yields "null" instead of "undefined"

[A. Sundararajan]

Hi,

Please approve backport of fix from jdk9 to jdk8u-dev. Fix applied "as 
is" with no jdk8 specific changes.

Bug: https://bugs.openjdk.java.net/browse/JDK-8044000
Webrev: http://cr.openjdk.java.net/~sundar/8044000/
jdk9 review thread: 
http://mail.openjdk.java.net/pipermail/nashorn-dev/2014-May/003016.html
jdk9 changeset: http://hg.openjdk.java.net/jdk9/dev/nashorn/rev/32b66f4661ea

Thanks
-Sundar