RFR(S): JDK-8143933: Create testlibrary for auxiliary methods used in g1/humongousObjects testing

[Kirill Zhaldybin]

Hi!

Could you please review the following patch that add auxiliary methods 
used by g1/humongousObjects tests to testlibrary?

These methods will be used by tests from JEP 278 
https://bugs.openjdk.java.net/browse/JDK-8139889


CR: https://bugs.openjdk.java.net/browse/JDK-8143933
Webrev: http://cr.openjdk.java.net/~kzhaldyb/webrevs/JDK-8143933/webrev.00/

Thank you.

Regards, Kirill