Patch to fix build breakage with GCC 4.7

[Deepak Bhole]

* Deepak Bhole <dbhole at redhat.com> [2012-01-27 16:48]:
> Hi,
> 
> HotSpot currently fails to build with GCC 4.7 due to 2 points where it
> is using boolean rather than NULL. GCC 4.6 treated it as a warning --
> 4.7 treats it as an error.
> 
> Attached patch fixes the issue and makes it build again.
> 

Sorry, old habit of posting just the patch.. webrev is here for those
who prefer it:
http://cr.openjdk.java.net/~dbhole/GCC-4.7-HS23.00/

Cheers,
Deepak