RFR (XS) 8175104: Unhandled oop in ProtectionDomainCacheTable::compute_hash

[coleen.phillimore at oracle.com]

Summary: Pass Handle for protection_domain as it is mostly a Handle up 
the call stack

See bug for more details.

open webrev at http://cr.openjdk.java.net/~coleenp/8175104.01/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8175104

Tested with JPRT.

Thanks,
Coleen