[Serialization] Ignore parsed declarations when resolving x-refs.
[Serialization] Ignore parsed declarations when resolving x-refs.

A cross-reference in a module cannot refer to a parsed entity, because the parsed entity couldn’t have been seen when the module was built. Filter these out, which prevents a crash in the subsequent commit.
shajrawi/swift,tkremenek/swift,aschwaighofer/swift,shahmishal/swift,karwa/swift,hughbe/swift,hooman/swift,devincoughlin/swift,practicalswift/swift,swiftix/swift,hughbe/swift,alblue/swift,jopamer/swift,OscarSwanros/swift,huonw/swift,return/swift,karwa/swift,jopamer/swift,zisko/swift,swiftix/swift,shahmishal/swift,milseman/swift,felix91gr/swift,danielmartin/swift,karwa/swift,gregomni/swift,practicalswift/swift,shajrawi/swift,benlangmuir/swift,harlanhaskins/swift,huonw/swift,jtbandes/swift,sschiau/swift,practicalswift/swift,atrick/swift,sschiau/swift,djwbrown/swift,felix91gr/swift,harlanhaskins/swift,alblue/swift,Jnosh/swift,gribozavr/swift,JGiola/swift,swiftix/swift,djwbrown/swift,shajrawi/swift,shahmishal/swift,deyton/swift,hughbe/swift,brentdax/swift,aschwaighofer/swift,roambotics/swift,gregomni/swift,jckarter/swift,return/swift,benlangmuir/swift,tjw/swift,austinzheng/swift,uasys/swift,jmgc/swift,stephentyrone/swift,harlanhaskins/swift,sschiau/swift,hooman/swift,ahoppen/swift,frootloops/swift,lorentey/swift,shahmishal/swift,apple/swift,rudkx/swift,parkera/swift,aschwaighofer/swift,shahmishal/swift,tjw/swift,jtbandes/swift,practicalswift/swift,parkera/swift,apple/swift,lorentey/swift,milseman/swift,huonw/swift,shajrawi/swift,austinzheng/swift,OscarSwanros/swift,uasys/swift,tkremenek/swift,shahmishal/swift,austinzheng/swift,OscarSwanros/swift,huonw/swift,allevato/swift,jtbandes/swift,tkremenek/swift,nathawes/swift,karwa/swift,jtbandes/swift,frootloops/swift,gregomni/swift,jckarter/swift,Jnosh/swift,aschwaighofer/swift,uasys/swift,tjw/swift,jmgc/swift,amraboelela/swift,CodaFi/swift,brentdax/swift,apple/swift,tjw/swift,danielmartin/swift,gribozavr/swift,harlanhaskins/swift,swiftix/swift,stephentyrone/swift,ahoppen/swift,deyton/swift,uasys/swift,sschiau/swift,harlanhaskins/swift,amraboelela/swift,rudkx/swift,airspeedswift/swift,CodaFi/swift,xedin/swift,parkera/swift,roambotics/swift,natecook1000/swift,atrick/swift,natecook1000/swift,austinzheng/swift,zisko/swift,natecook1000/swift,Jnosh/swift,practicalswift/swift,rudkx/swift,zisko/swift,calebd/swift,return/swift,benlangmuir/swift,djwbrown/swift,CodaFi/swift,milseman/swift,benlangmuir/swift,tjw/swift,brentdax/swift,airspeedswift/swift,sschiau/swift,danielmartin/swift,xwu/swift,Jnosh/swift,alblue/swift,jopamer/swift,Jnosh/swift,frootloops/swift,karwa/swift,parkera/swift,harlanhaskins/swift,jmgc/swift,jtbandes/swift,apple/swift,deyton/swift,jckarter/swift,gribozavr/swift,deyton/swift,JGiola/swift,airspeedswift/swift,devincoughlin/swift,aschwaighofer/swift,zisko/swift,devincoughlin/swift,gribozavr/swift,nathawes/swift,gribozavr/swift,benlangmuir/swift,gregomni/swift,benlangmuir/swift,CodaFi/swift,karwa/swift,frootloops/swift,natecook1000/swift,CodaFi/swift,roambotics/swift,OscarSwanros/swift,stephentyrone/swift,xedin/swift,swiftix/swift,xedin/swift,hooman/swift,nathawes/swift,OscarSwanros/swift,gribozavr/swift,parkera/swift,xwu/swift,brentdax/swift,sschiau/swift,rudkx/swift,swiftix/swift,hughbe/swift,lorentey/swift,xwu/swift,devincoughlin/swift,calebd/swift,allevato/swift,glessard/swift,jopamer/swift,airspeedswift/swift,glessard/swift,stephentyrone/swift,airspeedswift/swift,allevato/swift,xwu/swift,return/swift,tkremenek/swift,jtbandes/swift,deyton/swift,jopamer/swift,nathawes/swift,hooman/swift,huonw/swift,amraboelela/swift,felix91gr/swift,ahoppen/swift,karwa/swift,shajrawi/swift,jmgc/swift,tkremenek/swift,parkera/swift,nathawes/swift,jmgc/swift,practicalswift/swift,jckarter/swift,felix91gr/swift,ahoppen/swift,OscarSwanros/swift,frootloops/swift,parkera/swift,hooman/swift,hooman/swift,austinzheng/swift,djwbrown/swift,nathawes/swift,calebd/swift,amraboelela/swift,JGiola/swift,uasys/swift,calebd/swift,devincoughlin/swift,allevato/swift,OscarSwanros/swift,brentdax/swift,nathawes/swift,CodaFi/swift,hughbe/swift,devincoughlin/swift,austinzheng/swift,alblue/swift,zisko/swift,milseman/swift,hughbe/swift,Jnosh/swift,rudkx/swift,brentdax/swift,roambotics/swift,allevato/swift,roambotics/swift,frootloops/swift,jckarter/swift,zisko/swift,lorentey/swift,huonw/swift,jopamer/swift,practicalswift/swift,danielmartin/swift,calebd/swift,glessard/swift,deyton/swift,jckarter/swift,xedin/swift,sschiau/swift,frootloops/swift,Jnosh/swift,hooman/swift,deyton/swift,xwu/swift,milseman/swift,alblue/swift,gribozavr/swift,xedin/swift,glessard/swift,glessard/swift,devincoughlin/swift,felix91gr/swift,stephentyrone/swift,felix91gr/swift,aschwaighofer/swift,return/swift,JGiola/swift,tjw/swift,natecook1000/swift,rudkx/swift,jtbandes/swift,return/swift,aschwaighofer/swift,atrick/swift,amraboelela/swift,allevato/swift,calebd/swift,gregomni/swift,apple/swift,natecook1000/swift,gribozavr/swift,shahmishal/swift,amraboelela/swift,xedin/swift,alblue/swift,swiftix/swift,shajrawi/swift,stephentyrone/swift,xwu/swift,lorentey/swift,karwa/swift,alblue/swift,JGiola/swift,atrick/swift,allevato/swift,tkremenek/swift,return/swift,CodaFi/swift,danielmartin/swift,brentdax/swift,glessard/swift,jopamer/swift,uasys/swift,lorentey/swift,milseman/swift,ahoppen/swift,xedin/swift,JGiola/swift,airspeedswift/swift,danielmartin/swift,shajrawi/swift,tjw/swift,jmgc/swift,austinzheng/swift,uasys/swift,lorentey/swift,devincoughlin/swift,milseman/swift,xwu/swift,shajrawi/swift,atrick/swift,stephentyrone/swift,djwbrown/swift,zisko/swift,huonw/swift,ahoppen/swift,gregomni/swift,calebd/swift,jmgc/swift,apple/swift,amraboelela/swift,parkera/swift,xedin/swift,harlanhaskins/swift,sschiau/swift,roambotics/swift,djwbrown/swift,tkremenek/swift,hughbe/swift,atrick/swift,natecook1000/swift,shahmishal/swift,danielmartin/swift,practicalswift/swift,djwbrown/swift,airspeedswift/swift,lorentey/swift,jckarter/swift,felix91gr/swift