[Serialization] Factor out a helper for types that wrap other types
[Serialization] Factor out a helper for types that wrap other types

...and carry no other information (besides their record code).
No functionality change.

shajrawi/swift,gribozavr/swift,airspeedswift/swift,tkremenek/swift,apple/swift,sschiau/swift,sschiau/swift,benlangmuir/swift,glessard/swift,JGiola/swift,glessard/swift,tkremenek/swift,shahmishal/swift,parkera/swift,hooman/swift,shahmishal/swift,xwu/swift,aschwaighofer/swift,apple/swift,stephentyrone/swift,devincoughlin/swift,nathawes/swift,jckarter/swift,aschwaighofer/swift,allevato/swift,allevato/swift,atrick/swift,jmgc/swift,jmgc/swift,allevato/swift,shahmishal/swift,jmgc/swift,shahmishal/swift,JGiola/swift,harlanhaskins/swift,jmgc/swift,parkera/swift,parkera/swift,nathawes/swift,JGiola/swift,aschwaighofer/swift,stephentyrone/swift,apple/swift,sschiau/swift,ahoppen/swift,lorentey/swift,devincoughlin/swift,gribozavr/swift,nathawes/swift,devincoughlin/swift,gribozavr/swift,shahmishal/swift,parkera/swift,stephentyrone/swift,gribozavr/swift,airspeedswift/swift,karwa/swift,benlangmuir/swift,shajrawi/swift,xedin/swift,sschiau/swift,tkremenek/swift,jmgc/swift,CodaFi/swift,gribozavr/swift,jckarter/swift,atrick/swift,sschiau/swift,shahmishal/swift,rudkx/swift,CodaFi/swift,ahoppen/swift,airspeedswift/swift,hooman/swift,shajrawi/swift,karwa/swift,shajrawi/swift,rudkx/swift,aschwaighofer/swift,lorentey/swift,karwa/swift,airspeedswift/swift,gregomni/swift,shajrawi/swift,hooman/swift,tkremenek/swift,shajrawi/swift,roambotics/swift,devincoughlin/swift,rudkx/swift,hooman/swift,xedin/swift,gregomni/swift,nathawes/swift,roambotics/swift,xwu/swift,harlanhaskins/swift,harlanhaskins/swift,sschiau/swift,shahmishal/swift,CodaFi/swift,CodaFi/swift,hooman/swift,ahoppen/swift,airspeedswift/swift,karwa/swift,shajrawi/swift,jmgc/swift,CodaFi/swift,atrick/swift,xedin/swift,airspeedswift/swift,rudkx/swift,jckarter/swift,rudkx/swift,benlangmuir/swift,xwu/swift,xedin/swift,jckarter/swift,airspeedswift/swift,karwa/swift,gribozavr/swift,aschwaighofer/swift,stephentyrone/swift,nathawes/swift,glessard/swift,gregomni/swift,lorentey/swift,xwu/swift,sschiau/swift,xwu/swift,harlanhaskins/swift,xedin/swift,jckarter/swift,roambotics/swift,devincoughlin/swift,lorentey/swift,harlanhaskins/swift,stephentyrone/swift,harlanhaskins/swift,tkremenek/swift,CodaFi/swift,parkera/swift,stephentyrone/swift,nathawes/swift,parkera/swift,sschiau/swift,tkremenek/swift,hooman/swift,xedin/swift,glessard/swift,gregomni/swift,nathawes/swift,benlangmuir/swift,JGiola/swift,benlangmuir/swift,devincoughlin/swift,ahoppen/swift,shahmishal/swift,xwu/swift,roambotics/swift,harlanhaskins/swift,apple/swift,hooman/swift,allevato/swift,lorentey/swift,allevato/swift,roambotics/swift,allevato/swift,ahoppen/swift,karwa/swift,benlangmuir/swift,CodaFi/swift,jckarter/swift,jmgc/swift,atrick/swift,gribozavr/swift,gregomni/swift,devincoughlin/swift,stephentyrone/swift,JGiola/swift,tkremenek/swift,xedin/swift,atrick/swift,aschwaighofer/swift,atrick/swift,karwa/swift,gribozavr/swift,shajrawi/swift,rudkx/swift,parkera/swift,apple/swift,glessard/swift,roambotics/swift,gregomni/swift,allevato/swift,ahoppen/swift,apple/swift,jckarter/swift,xedin/swift,JGiola/swift,lorentey/swift,lorentey/swift,glessard/swift,devincoughlin/swift,parkera/swift,aschwaighofer/swift,karwa/swift,lorentey/swift,xwu/swift