RFR 8061257: nashorn ant build script should have a sanity target

[Hannes Wallnoefer]

+1

I tested and it builds correctly with jdk8 and 9 and reports the proper 
error with jdk7.

Hannes

Am 2014-10-20 um 06:22 schrieb A. Sundararajan:
> Please review http://cr.openjdk.java.net/~sundar/8061257/ for 
> https://bugs.openjdk.java.net/browse/JDK-8061257
>
> Thanks,
> -Sundar