Fix for 8013633, fix platform ifdefs in unsafe.cpp

[David Holmes]

Hi Bill,

On 1/05/2013 4:55 AM, bill.pittore at oracle.com wrote:
> Rather than add yet another platform to the ifdefs in unsafe.cpp we
> thought it would be cleaner to reference
> #ifdef SUPPORTS_NATIVE_CX8
>
> which is set in platform specific globalsDefinitions_<arch>.hpp file
>
> Webrev is here:
> http://cr.openjdk.java.net/~bpittore/8013633/webrev.00/

Remove the comments

! // Sparc, X86, and ARM v7a have atomic jlong (8 bytes) instructions

Not much point moving away from a list of architectures in the ifdef if 
you are going to add them to the comment anyway :)

Otherwise looks good to me.

Thanks,
David

> thanks,
> bill