RFR (XXS): 7118647: compressed oops crashes on MacOS X with JPRT GCBasher test

[James Melvin]

Hi,

Please review this change to fix and re-enable Compressed OOPs support
on Mac OS X. The solution for now is to relax the problem assertion to
simply check for COOP mode rather than an exact address. This should be
sufficient until zero-based addressing logic can be refined.

WEBREV:
   http://cr.openjdk.java.net/~jmelvin/7118647/webrev.00

TESTS:
   Successfully reran the failing testcase
   Confirmed COOPs was enabled with and without -XX:+UseCompressedOops

Thanks to Vladimir Kozlov and Coleen Phillimore for their support!

Jim