RFR 8173257: test/script/trusted/JDK-8021189.js and test/script/trusted/JDK-8021129.js fail in nashorn nightly

[Sundararajan Athijegannathan]

Please review http://cr.openjdk.java.net/~sundar/8173257/webrev.00/ for 
https://bugs.openjdk.java.net/browse/JDK-8173257

Thanks,
-Sundar