RFR (S): 8019518: PPC64 (part 103): cppInterpreter: implement support for compressed Oops

[Lindenmaier, Goetz]

Hi,

we implemented the missing decode in aaload so that the
cppInterpreter now works with compressed Oops.
http://cr.openjdk.java.net/~goetz/webrevs/8019518-cInterp_cOops/

Please review this change.

Thanks and best regards,
  Goetz.