RFR: JDK-8075586: add @modules as needed to the open hotspot tests

[Alexander Kulyakhtin]

Hi,

Could you, please, review the fix below.

CR: https://bugs.openjdk.java.net/browse/JDK-8075586
webrev: http://cr.openjdk.java.net/~tpivovarova/akulyakh/8075586/webrev.00/

The fix adds @modules keyword to the existing hotspot tests, as needed, so that the tests can access the required API when the new modular architecture is in place.

Best regards,
Alex