[Serialization] Simplify metatype and function type serialization
[Serialization] Simplify metatype and function type serialization

No functionality change.

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