RFR: 8213819 : doclint should warn against {@index} inside tag

[Priya Lakshmi Muthuswamy]

Hi,

Kindly review the fix for https://bugs.openjdk.java.net/browse/JDK-8213819
webrev : http://cr.openjdk.java.net/~pmuthuswamy/8213819/webrev.00/

Thanks,
Priya