Added more prototypes for the msvc atomics

Change-Id: Iaee5efb23c04518218240017db6d1d44aba2dda4
Reviewed-on: http://review.couchbase.org/31208
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>