RFR: JDK-8054836 [TESTBUG] Test is needed to verify correctness of malloc tracking

[George Triantafillou]

Please review this new native memory tracking test for 8054836.  The 
test allocates small amounts of memory with random pseudo call stacks 
using the WhiteBox API:

Webrev: http://cr.openjdk.java.net/~gtriantafill/8054836/webrev/ 
<http://cr.openjdk.java.net/%7Egtriantafill/8054836/webrev/>
Bug: https://bugs.openjdk.java.net/browse/JDK-8054836

The fix was tested locally on Linux with jtreg.

Thanks.

-George