RFR: 8154843: GC tests should be correctly marked with @module

[Michail Chernov]

Hi,

Could you please take a look at this change which adds @modules to 
existing tests?

http://cr.openjdk.java.net/~mchernov/8154843/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8154843

Testing is in progress.

Thanks,
Michail