10 RFR(xs): 8177551: [TESTBUG] TestHumongousClassLoader.java can fail on systems with non-g1 collector.

[Michail Chernov]

Hi,

Could I have a review for this small fix please?

https://bugs.openjdk.java.net/browse/JDK-8177551
http://cr.openjdk.java.net/~mchernov/8177551/webrev.00/

TestHumongousClassLoader.java may cause to execute G1 specific code with 
non-G1 collector.  ClassLoaderGenerator should be executed with 
explicitly defined -XX:+UseG1GC because it instantiates G1SampleClass 
which has G1 specific WhiteBox methods.

Thanks,
Michail