[Clang Importer] Cleanup and sharing of code
[Clang Importer] Cleanup and sharing of code

Adds makeStructRawValued utility function, which shares common code
for raw-value-backed structs from both OptionSets and many imported
enums. NFC.

austinzheng/swift,uasys/swift,atrick/swift,bitjammer/swift,ahoppen/swift,deyton/swift,apple/swift,tardieu/swift,bitjammer/swift,arvedviehweger/swift,milseman/swift,sschiau/swift,amraboelela/swift,sschiau/swift,glessard/swift,ahoppen/swift,milseman/swift,return/swift,modocache/swift,danielmartin/swift,aschwaighofer/swift,allevato/swift,nathawes/swift,russbishop/swift,shajrawi/swift,lorentey/swift,frootloops/swift,benlangmuir/swift,manavgabhawala/swift,gmilos/swift,shahmishal/swift,practicalswift/swift,tinysun212/swift-windows,jtbandes/swift,shahmishal/swift,gottesmm/swift,atrick/swift,return/swift,jtbandes/swift,gmilos/swift,tinysun212/swift-windows,danielmartin/swift,felix91gr/swift,manavgabhawala/swift,xedin/swift,JGiola/swift,tinysun212/swift-windows,zisko/swift,benlangmuir/swift,nathawes/swift,IngmarStein/swift,airspeedswift/swift,natecook1000/swift,aschwaighofer/swift,alblue/swift,austinzheng/swift,airspeedswift/swift,karwa/swift,OscarSwanros/swift,airspeedswift/swift,codestergit/swift,danielmartin/swift,hooman/swift,Jnosh/swift,djwbrown/swift,tjw/swift,roambotics/swift,alblue/swift,airspeedswift/swift,apple/swift,shahmishal/swift,amraboelela/swift,arvedviehweger/swift,russbishop/swift,karwa/swift,devincoughlin/swift,IngmarStein/swift,ken0nek/swift,tardieu/swift,roambotics/swift,gribozavr/swift,CodaFi/swift,glessard/swift,harlanhaskins/swift,benlangmuir/swift,gregomni/swift,hooman/swift,therealbnut/swift,aschwaighofer/swift,milseman/swift,JaSpa/swift,devincoughlin/swift,return/swift,zisko/swift,amraboelela/swift,calebd/swift,Jnosh/swift,sschiau/swift,tjw/swift,kstaring/swift,gottesmm/swift,deyton/swift,felix91gr/swift,swiftix/swift,felix91gr/swift,lorentey/swift,huonw/swift,ken0nek/swift,therealbnut/swift,return/swift,milseman/swift,benlangmuir/swift,harlanhaskins/swift,allevato/swift,xwu/swift,glessard/swift,gmilos/swift,gottesmm/swift,huonw/swift,lorentey/swift,glessard/swift,therealbnut/swift,russbishop/swift,zisko/swift,karwa/swift,danielmartin/swift,hooman/swift,huonw/swift,parkera/swift,OscarSwanros/swift,jmgc/swift,manavgabhawala/swift,aschwaighofer/swift,parkera/swift,jckarter/swift,tardieu/swift,djwbrown/swift,gregomni/swift,devincoughlin/swift,tkremenek/swift,modocache/swift,tkremenek/swift,benlangmuir/swift,devincoughlin/swift,zisko/swift,jckarter/swift,nathawes/swift,hughbe/swift,xedin/swift,felix91gr/swift,ahoppen/swift,brentdax/swift,hooman/swift,alblue/swift,karwa/swift,sschiau/swift,natecook1000/swift,gmilos/swift,djwbrown/swift,huonw/swift,ken0nek/swift,jtbandes/swift,jmgc/swift,shahmishal/swift,tjw/swift,practicalswift/swift,JGiola/swift,stephentyrone/swift,hughbe/swift,milseman/swift,therealbnut/swift,atrick/swift,shahmishal/swift,brentdax/swift,devincoughlin/swift,jckarter/swift,swiftix/swift,arvedviehweger/swift,hughbe/swift,jopamer/swift,djwbrown/swift,jopamer/swift,brentdax/swift,lorentey/swift,harlanhaskins/swift,jtbandes/swift,ben-ng/swift,ben-ng/swift,shajrawi/swift,xwu/swift,rudkx/swift,zisko/swift,tkremenek/swift,swiftix/swift,ken0nek/swift,nathawes/swift,practicalswift/swift,xwu/swift,tkremenek/swift,devincoughlin/swift,austinzheng/swift,calebd/swift,xwu/swift,kstaring/swift,stephentyrone/swift,kstaring/swift,CodaFi/swift,shajrawi/swift,therealbnut/swift,CodaFi/swift,kperryua/swift,sschiau/swift,gribozavr/swift,huonw/swift,parkera/swift,huonw/swift,lorentey/swift,uasys/swift,tardieu/swift,russbishop/swift,harlanhaskins/swift,dreamsxin/swift,jmgc/swift,OscarSwanros/swift,brentdax/swift,Jnosh/swift,tkremenek/swift,russbishop/swift,natecook1000/swift,ben-ng/swift,jopamer/swift,gottesmm/swift,modocache/swift,harlanhaskins/swift,uasys/swift,lorentey/swift,roambotics/swift,bitjammer/swift,jtbandes/swift,ben-ng/swift,stephentyrone/swift,IngmarStein/swift,modocache/swift,JaSpa/swift,shajrawi/swift,Jnosh/swift,rudkx/swift,felix91gr/swift,Jnosh/swift,ahoppen/swift,atrick/swift,ken0nek/swift,tkremenek/swift,jopamer/swift,uasys/swift,ben-ng/swift,ben-ng/swift,jckarter/swift,gmilos/swift,frootloops/swift,JaSpa/swift,kstaring/swift,hughbe/swift,ben-ng/swift,hooman/swift,djwbrown/swift,harlanhaskins/swift,russbishop/swift,shajrawi/swift,amraboelela/swift,codestergit/swift,rudkx/swift,deyton/swift,harlanhaskins/swift,frootloops/swift,felix91gr/swift,sschiau/swift,xedin/swift,stephentyrone/swift,tjw/swift,tinysun212/swift-windows,glessard/swift,allevato/swift,calebd/swift,karwa/swift,tardieu/swift,codestergit/swift,felix91gr/swift,brentdax/swift,JGiola/swift,milseman/swift,parkera/swift,airspeedswift/swift,atrick/swift,stephentyrone/swift,jtbandes/swift,rudkx/swift,OscarSwanros/swift,practicalswift/swift,gmilos/swift,jmgc/swift,devincoughlin/swift,stephentyrone/swift,gregomni/swift,alblue/swift,allevato/swift,arvedviehweger/swift,natecook1000/swift,manavgabhawala/swift,xwu/swift,gottesmm/swift,aschwaighofer/swift,allevato/swift,OscarSwanros/swift,xwu/swift,deyton/swift,OscarSwanros/swift,bitjammer/swift,manavgabhawala/swift,Jnosh/swift,OscarSwanros/swift,therealbnut/swift,apple/swift,parkera/swift,austinzheng/swift,kperryua/swift,calebd/swift,austinzheng/swift,deyton/swift,amraboelela/swift,xedin/swift,tardieu/swift,codestergit/swift,rudkx/swift,calebd/swift,manavgabhawala/swift,apple/swift,tjw/swift,JaSpa/swift,gottesmm/swift,danielmartin/swift,modocache/swift,allevato/swift,parkera/swift,frootloops/swift,gottesmm/swift,tkremenek/swift,frootloops/swift,return/swift,hughbe/swift,benlangmuir/swift,amraboelela/swift,karwa/swift,swiftix/swift,ken0nek/swift,jmgc/swift,JaSpa/swift,zisko/swift,kperryua/swift,tinysun212/swift-windows,bitjammer/swift,gribozavr/swift,devincoughlin/swift,IngmarStein/swift,lorentey/swift,apple/swift,uasys/swift,alblue/swift,gribozavr/swift,hooman/swift,atrick/swift,hughbe/swift,rudkx/swift,kperryua/swift,deyton/swift,airspeedswift/swift,nathawes/swift,codestergit/swift,IngmarStein/swift,CodaFi/swift,tardieu/swift,modocache/swift,milseman/swift,gribozavr/swift,austinzheng/swift,CodaFi/swift,gregomni/swift,roambotics/swift,JaSpa/swift,djwbrown/swift,kperryua/swift,danielmartin/swift,practicalswift/swift,IngmarStein/swift,gribozavr/swift,tjw/swift,gribozavr/swift,sschiau/swift,practicalswift/swift,natecook1000/swift,jopamer/swift,kstaring/swift,glessard/swift,sschiau/swift,jckarter/swift,JGiola/swift,arvedviehweger/swift,calebd/swift,karwa/swift,ahoppen/swift,uasys/swift,jopamer/swift,kstaring/swift,return/swift,natecook1000/swift,practicalswift/swift,huonw/swift,brentdax/swift,jckarter/swift,kperryua/swift,swiftix/swift,allevato/swift,jopamer/swift,shahmishal/swift,hughbe/swift,IngmarStein/swift,shajrawi/swift,return/swift,swiftix/swift,xwu/swift,jmgc/swift,jmgc/swift,modocache/swift,apple/swift,bitjammer/swift,alblue/swift,xedin/swift,roambotics/swift,JaSpa/swift,kstaring/swift,codestergit/swift,frootloops/swift,Jnosh/swift,djwbrown/swift,austinzheng/swift,bitjammer/swift,gregomni/swift,codestergit/swift,stephentyrone/swift,tjw/swift,xedin/swift,aschwaighofer/swift,tinysun212/swift-windows,xedin/swift,nathawes/swift,brentdax/swift,CodaFi/swift,lorentey/swift,aschwaighofer/swift,parkera/swift,ken0nek/swift,dreamsxin/swift,therealbnut/swift,danielmartin/swift,natecook1000/swift,alblue/swift,airspeedswift/swift,calebd/swift,shahmishal/swift,practicalswift/swift,gribozavr/swift,arvedviehweger/swift,roambotics/swift,shajrawi/swift,shajrawi/swift,hooman/swift,manavgabhawala/swift,zisko/swift,russbishop/swift,arvedviehweger/swift,amraboelela/swift,tinysun212/swift-windows,JGiola/swift,jckarter/swift,JGiola/swift,karwa/swift,xedin/swift,parkera/swift,uasys/swift,CodaFi/swift,ahoppen/swift,deyton/swift,gregomni/swift,frootloops/swift,gmilos/swift,swiftix/swift,jtbandes/swift,shahmishal/swift,nathawes/swift,kperryua/swift