RFR for JDK-8030284 TEST_BUG: intermittent StackOverflow in RMI bench/serial test

[Tristan Yan]

Hi Everyone

Please help to review the fix for JDK-8030284.

http://cr.openjdk.java.net/~tyan/JDK-8030284/webrev.00/ 
<http://cr.openjdk.java.net/%7Etyan/JDK-8030284/webrev.00/>

This is a one line fix that add -Xss to prevent StackOverflowError.

Thank you
Tristan