IRGen: Fix -sil-serialize-all linkage issue
IRGen: Fix -sil-serialize-all linkage issue

External private definitions coming from a -sil-serialize-all
module must be effectively public at the LLVM level too, fixing
a linker error when referencing closures from a deserialized
function body.

CodaFi/swift,parkera/swift,atrick/swift,hughbe/swift,glessard/swift,karwa/swift,codestergit/swift,milseman/swift,brentdax/swift,parkera/swift,tkremenek/swift,shahmishal/swift,natecook1000/swift,harlanhaskins/swift,austinzheng/swift,amraboelela/swift,codestergit/swift,aschwaighofer/swift,codestergit/swift,tinysun212/swift-windows,rudkx/swift,aschwaighofer/swift,zisko/swift,apple/swift,hooman/swift,hooman/swift,xedin/swift,jckarter/swift,felix91gr/swift,atrick/swift,sschiau/swift,benlangmuir/swift,Jnosh/swift,harlanhaskins/swift,danielmartin/swift,benlangmuir/swift,huonw/swift,return/swift,OscarSwanros/swift,parkera/swift,glessard/swift,karwa/swift,zisko/swift,felix91gr/swift,xwu/swift,arvedviehweger/swift,tkremenek/swift,JGiola/swift,devincoughlin/swift,jtbandes/swift,natecook1000/swift,devincoughlin/swift,sschiau/swift,parkera/swift,Jnosh/swift,zisko/swift,huonw/swift,shajrawi/swift,practicalswift/swift,huonw/swift,lorentey/swift,jckarter/swift,JGiola/swift,xwu/swift,natecook1000/swift,natecook1000/swift,alblue/swift,roambotics/swift,tjw/swift,stephentyrone/swift,xwu/swift,djwbrown/swift,jckarter/swift,amraboelela/swift,OscarSwanros/swift,tinysun212/swift-windows,allevato/swift,aschwaighofer/swift,frootloops/swift,shajrawi/swift,roambotics/swift,uasys/swift,deyton/swift,deyton/swift,gregomni/swift,tkremenek/swift,jmgc/swift,parkera/swift,devincoughlin/swift,hooman/swift,gribozavr/swift,practicalswift/swift,devincoughlin/swift,djwbrown/swift,tjw/swift,djwbrown/swift,codestergit/swift,stephentyrone/swift,shajrawi/swift,nathawes/swift,ahoppen/swift,gribozavr/swift,lorentey/swift,uasys/swift,calebd/swift,xedin/swift,lorentey/swift,austinzheng/swift,benlangmuir/swift,austinzheng/swift,uasys/swift,codestergit/swift,shajrawi/swift,nathawes/swift,calebd/swift,jopamer/swift,return/swift,parkera/swift,hughbe/swift,austinzheng/swift,jmgc/swift,sschiau/swift,hughbe/swift,jopamer/swift,karwa/swift,jckarter/swift,danielmartin/swift,atrick/swift,airspeedswift/swift,hughbe/swift,uasys/swift,codestergit/swift,natecook1000/swift,jmgc/swift,brentdax/swift,airspeedswift/swift,nathawes/swift,karwa/swift,danielmartin/swift,rudkx/swift,frootloops/swift,alblue/swift,calebd/swift,return/swift,gregomni/swift,harlanhaskins/swift,airspeedswift/swift,deyton/swift,lorentey/swift,arvedviehweger/swift,tjw/swift,jmgc/swift,jckarter/swift,roambotics/swift,devincoughlin/swift,shahmishal/swift,swiftix/swift,deyton/swift,shajrawi/swift,aschwaighofer/swift,jtbandes/swift,sschiau/swift,jmgc/swift,felix91gr/swift,roambotics/swift,karwa/swift,uasys/swift,frootloops/swift,parkera/swift,xedin/swift,milseman/swift,apple/swift,practicalswift/swift,devincoughlin/swift,frootloops/swift,natecook1000/swift,shahmishal/swift,hughbe/swift,hooman/swift,CodaFi/swift,aschwaighofer/swift,brentdax/swift,lorentey/swift,amraboelela/swift,tkremenek/swift,swiftix/swift,milseman/swift,jtbandes/swift,jopamer/swift,shahmishal/swift,gribozavr/swift,tkremenek/swift,aschwaighofer/swift,shahmishal/swift,amraboelela/swift,djwbrown/swift,karwa/swift,jtbandes/swift,rudkx/swift,jmgc/swift,nathawes/swift,frootloops/swift,amraboelela/swift,atrick/swift,CodaFi/swift,brentdax/swift,austinzheng/swift,gribozavr/swift,sschiau/swift,rudkx/swift,parkera/swift,ahoppen/swift,atrick/swift,roambotics/swift,devincoughlin/swift,benlangmuir/swift,hughbe/swift,jtbandes/swift,alblue/swift,xedin/swift,tinysun212/swift-windows,zisko/swift,return/swift,felix91gr/swift,natecook1000/swift,atrick/swift,stephentyrone/swift,tinysun212/swift-windows,benlangmuir/swift,shahmishal/swift,xedin/swift,practicalswift/swift,karwa/swift,swiftix/swift,deyton/swift,airspeedswift/swift,djwbrown/swift,uasys/swift,apple/swift,jckarter/swift,zisko/swift,apple/swift,nathawes/swift,lorentey/swift,tjw/swift,ahoppen/swift,tinysun212/swift-windows,tkremenek/swift,gregomni/swift,CodaFi/swift,sschiau/swift,return/swift,huonw/swift,practicalswift/swift,gregomni/swift,xedin/swift,shahmishal/swift,return/swift,JGiola/swift,tinysun212/swift-windows,frootloops/swift,amraboelela/swift,Jnosh/swift,calebd/swift,milseman/swift,allevato/swift,Jnosh/swift,huonw/swift,apple/swift,tjw/swift,shajrawi/swift,huonw/swift,lorentey/swift,calebd/swift,harlanhaskins/swift,harlanhaskins/swift,roambotics/swift,jopamer/swift,tjw/swift,allevato/swift,felix91gr/swift,hooman/swift,gribozavr/swift,xwu/swift,gribozavr/swift,JGiola/swift,Jnosh/swift,benlangmuir/swift,calebd/swift,gregomni/swift,lorentey/swift,danielmartin/swift,brentdax/swift,CodaFi/swift,stephentyrone/swift,gribozavr/swift,gribozavr/swift,ahoppen/swift,stephentyrone/swift,glessard/swift,glessard/swift,arvedviehweger/swift,harlanhaskins/swift,stephentyrone/swift,practicalswift/swift,uasys/swift,xedin/swift,zisko/swift,tkremenek/swift,OscarSwanros/swift,ahoppen/swift,alblue/swift,xwu/swift,tinysun212/swift-windows,shahmishal/swift,danielmartin/swift,alblue/swift,brentdax/swift,sschiau/swift,jopamer/swift,jtbandes/swift,jopamer/swift,JGiola/swift,huonw/swift,airspeedswift/swift,hughbe/swift,apple/swift,stephentyrone/swift,rudkx/swift,jckarter/swift,sschiau/swift,jtbandes/swift,OscarSwanros/swift,codestergit/swift,devincoughlin/swift,nathawes/swift,OscarSwanros/swift,deyton/swift,Jnosh/swift,allevato/swift,alblue/swift,OscarSwanros/swift,allevato/swift,arvedviehweger/swift,harlanhaskins/swift,deyton/swift,hooman/swift,austinzheng/swift,practicalswift/swift,arvedviehweger/swift,djwbrown/swift,felix91gr/swift,glessard/swift,karwa/swift,brentdax/swift,austinzheng/swift,allevato/swift,shajrawi/swift,CodaFi/swift,return/swift,aschwaighofer/swift,CodaFi/swift,hooman/swift,nathawes/swift,ahoppen/swift,gregomni/swift,danielmartin/swift,tjw/swift,arvedviehweger/swift,frootloops/swift,swiftix/swift,djwbrown/swift,milseman/swift,rudkx/swift,felix91gr/swift,shajrawi/swift,JGiola/swift,milseman/swift,jmgc/swift,xwu/swift,danielmartin/swift,xedin/swift,OscarSwanros/swift,airspeedswift/swift,amraboelela/swift,glessard/swift,calebd/swift,practicalswift/swift,Jnosh/swift,milseman/swift,swiftix/swift,airspeedswift/swift,jopamer/swift,alblue/swift,xwu/swift,allevato/swift,arvedviehweger/swift,zisko/swift,swiftix/swift,swiftix/swift