RFR(XS): 8131328: Restore demo/jvmti tests

[Yekaterina Kantserova]

Hi,

Could I please have a review of this fix. demo/jvmti tests were 
unintentionally removed by 
https://bugs.openjdk.java.net/browse/JDK-8076471. This fix will restore 
the tests unrelated to hprof.

bug: https://bugs.openjdk.java.net/browse/JDK-8131328
webrev: http://cr.openjdk.java.net/~ykantser/8131328/webrev.00

Thanks,
Katja