[8u] RFR 8151486: Class.forName causes memory leak

[Aleksey Shipilev]

Original bug:
  https://bugs.openjdk.java.net/browse/JDK-8151486
  http://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/1f044f413e6c

The product change is exactly the same. I had to massage the test to work on 8u, though:
jdk.testlibrary.JarUtils is in different place, and has a little different method we should use for
createJarFile. The test fails without the product change, and passes with it.

8u webrev:
   http://cr.openjdk.java.net/~shade/8151486/webrev.8u.01/

Testing: new test, "tier1"-like profile

-- 
Thanks,
-Aleksey