RFR: 8075249: Cleanup forward_to_atomic and ClaimedForwardPtr

[Stefan Karlsson]

Hi,

Please  remove this patch to remove some coupling between ParNew, G1, 
and ParCompact.

oopDesc::forward_to_atomic is used by ParNew and G1, but it contains a 
call to ParNew specific code.

It's defined in oop.pcgc.inline.hpp, which is a ParCompact specific file.

I propose that we fix both issues by moving forward_to_atomic to 
oop.inline.hpp and move the ParNew specific code out to ParNew.

http://cr.openjdk.java.net/~stefank/8075249/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8075249

Thanks,
StefanK