[SIL-opaque] Add section-level comment explaining storage allocation
[SIL-opaque] Add section-level comment explaining storage allocation

atrick/swift,apple/swift,ahoppen/swift,glessard/swift,ahoppen/swift,gregomni/swift,benlangmuir/swift,gregomni/swift,rudkx/swift,roambotics/swift,roambotics/swift,ahoppen/swift,apple/swift,atrick/swift,roambotics/swift,roambotics/swift,JGiola/swift,benlangmuir/swift,rudkx/swift,roambotics/swift,apple/swift,rudkx/swift,glessard/swift,glessard/swift,rudkx/swift,JGiola/swift,glessard/swift,JGiola/swift,gregomni/swift,atrick/swift,benlangmuir/swift,ahoppen/swift,JGiola/swift,benlangmuir/swift,ahoppen/swift,apple/swift,roambotics/swift,glessard/swift,JGiola/swift,ahoppen/swift,benlangmuir/swift,JGiola/swift,apple/swift,atrick/swift,benlangmuir/swift,atrick/swift,rudkx/swift,apple/swift,gregomni/swift,gregomni/swift,glessard/swift,atrick/swift,rudkx/swift,gregomni/swift