[m-rev.] for review: Add support for weak pointers to the C RTS

[Paul Bone]

On Tue, Apr 15, 2014 at 10:20:01PM +1000, Paul Bone wrote:
> For review by anyone.
> 

No-one has reviewed these changes in the last three months so I've committed
them:

 + Make version_array's rewind code use constant stack space.
 + Add missing MR_GC_malloc_atomic procedure
 + Add support for weak pointers to the C RTS


-- 
Paul Bone