For ClangImporter::verifyAllModules() be defensive and avoid verifying while iterating the map of imported decls.
For ClangImporter::verifyAllModules() be defensive and avoid verifying while
iterating the map of imported decls.

Swift SVN r12720

frootloops/swift,SwiftAndroid/swift,SwiftAndroid/swift,hughbe/swift,nathawes/swift,tardieu/swift,khizkhiz/swift,benlangmuir/swift,felix91gr/swift,tardieu/swift,glessard/swift,therealbnut/swift,ahoppen/swift,stephentyrone/swift,gmilos/swift,aschwaighofer/swift,karwa/swift,xwu/swift,bitjammer/swift,jopamer/swift,ken0nek/swift,kusl/swift,johnno1962d/swift,devincoughlin/swift,karwa/swift,jtbandes/swift,khizkhiz/swift,adrfer/swift,modocache/swift,tardieu/swift,JaSpa/swift,apple/swift,tjw/swift,allevato/swift,mightydeveloper/swift,natecook1000/swift,ken0nek/swift,ken0nek/swift,cbrentharris/swift,gregomni/swift,alblue/swift,sschiau/swift,parkera/swift,kentya6/swift,khizkhiz/swift,swiftix/swift.old,uasys/swift,deyton/swift,kstaring/swift,kentya6/swift,gregomni/swift,shajrawi/swift,adrfer/swift,OscarSwanros/swift,ben-ng/swift,kusl/swift,CodaFi/swift,swiftix/swift,slavapestov/swift,swiftix/swift.old,hughbe/swift,adrfer/swift,sdulal/swift,adrfer/swift,milseman/swift,gmilos/swift,djwbrown/swift,manavgabhawala/swift,tkremenek/swift,xedin/swift,alblue/swift,parkera/swift,manavgabhawala/swift,xedin/swift,allevato/swift,frootloops/swift,IngmarStein/swift,gribozavr/swift,devincoughlin/swift,sschiau/swift,shahmishal/swift,lorentey/swift,swiftix/swift,hooman/swift,nathawes/swift,nathawes/swift,ken0nek/swift,dreamsxin/swift,hughbe/swift,jmgc/swift,deyton/swift,parkera/swift,uasys/swift,xwu/swift,gottesmm/swift,slavapestov/swift,SwiftAndroid/swift,KrishMunot/swift,sschiau/swift,calebd/swift,aschwaighofer/swift,zisko/swift,russbishop/swift,alblue/swift,roambotics/swift,milseman/swift,xwu/swift,JaSpa/swift,KrishMunot/swift,atrick/swift,MukeshKumarS/Swift,rudkx/swift,gottesmm/swift,jtbandes/swift,jmgc/swift,return/swift,devincoughlin/swift,kusl/swift,Jnosh/swift,glessard/swift,aschwaighofer/swift,cbrentharris/swift,tjw/swift,jopamer/swift,parkera/swift,OscarSwanros/swift,djwbrown/swift,CodaFi/swift,uasys/swift,gribozavr/swift,slavapestov/swift,calebd/swift,dreamsxin/swift,tardieu/swift,gregomni/swift,LeoShimonaka/swift,huonw/swift,felix91gr/swift,hooman/swift,danielmartin/swift,milseman/swift,OscarSwanros/swift,shajrawi/swift,rudkx/swift,kusl/swift,modocache/swift,therealbnut/swift,deyton/swift,rudkx/swift,tjw/swift,tkremenek/swift,calebd/swift,IngmarStein/swift,kstaring/swift,russbishop/swift,therealbnut/swift,hughbe/swift,jtbandes/swift,OscarSwanros/swift,ahoppen/swift,tkremenek/swift,CodaFi/swift,gottesmm/swift,Ivacker/swift,xedin/swift,kusl/swift,milseman/swift,LeoShimonaka/swift,MukeshKumarS/Swift,johnno1962d/swift,jtbandes/swift,jtbandes/swift,allevato/swift,jmgc/swift,karwa/swift,devincoughlin/swift,gregomni/swift,CodaFi/swift,Ivacker/swift,emilstahl/swift,manavgabhawala/swift,sdulal/swift,bitjammer/swift,return/swift,tardieu/swift,KrishMunot/swift,brentdax/swift,atrick/swift,amraboelela/swift,modocache/swift,arvedviehweger/swift,codestergit/swift,atrick/swift,arvedviehweger/swift,sdulal/swift,manavgabhawala/swift,sdulal/swift,nathawes/swift,amraboelela/swift,khizkhiz/swift,mightydeveloper/swift,benlangmuir/swift,KrishMunot/swift,emilstahl/swift,roambotics/swift,practicalswift/swift,adrfer/swift,cbrentharris/swift,hughbe/swift,johnno1962d/swift,swiftix/swift,sschiau/swift,roambotics/swift,glessard/swift,LeoShimonaka/swift,johnno1962d/swift,zisko/swift,jopamer/swift,stephentyrone/swift,practicalswift/swift,bitjammer/swift,xwu/swift,dduan/swift,johnno1962d/swift,IngmarStein/swift,jmgc/swift,KrishMunot/swift,lorentey/swift,airspeedswift/swift,swiftix/swift.old,djwbrown/swift,atrick/swift,johnno1962d/swift,frootloops/swift,felix91gr/swift,austinzheng/swift,parkera/swift,stephentyrone/swift,russbishop/swift,glessard/swift,modocache/swift,practicalswift/swift,calebd/swift,huonw/swift,emilstahl/swift,ahoppen/swift,xwu/swift,JGiola/swift,tkremenek/swift,arvedviehweger/swift,lorentey/swift,codestergit/swift,practicalswift/swift,atrick/swift,swiftix/swift,apple/swift,ben-ng/swift,harlanhaskins/swift,SwiftAndroid/swift,kstaring/swift,bitjammer/swift,tardieu/swift,apple/swift,frootloops/swift,felix91gr/swift,jckarter/swift,ken0nek/swift,johnno1962d/swift,khizkhiz/swift,natecook1000/swift,stephentyrone/swift,LeoShimonaka/swift,LeoShimonaka/swift,devincoughlin/swift,allevato/swift,Ivacker/swift,austinzheng/swift,parkera/swift,shahmishal/swift,CodaFi/swift,shajrawi/swift,JGiola/swift,kperryua/swift,gottesmm/swift,huonw/swift,djwbrown/swift,kperryua/swift,karwa/swift,MukeshKumarS/Swift,amraboelela/swift,kentya6/swift,roambotics/swift,ahoppen/swift,amraboelela/swift,swiftix/swift,kusl/swift,jckarter/swift,lorentey/swift,slavapestov/swift,frootloops/swift,gribozavr/swift,alblue/swift,therealbnut/swift,brentdax/swift,cbrentharris/swift,slavapestov/swift,gregomni/swift,mightydeveloper/swift,deyton/swift,hooman/swift,practicalswift/swift,IngmarStein/swift,cbrentharris/swift,swiftix/swift.old,kperryua/swift,brentdax/swift,SwiftAndroid/swift,emilstahl/swift,JGiola/swift,MukeshKumarS/Swift,JaSpa/swift,uasys/swift,manavgabhawala/swift,aschwaighofer/swift,lorentey/swift,kperryua/swift,shahmishal/swift,SwiftAndroid/swift,ben-ng/swift,Ivacker/swift,Ivacker/swift,karwa/swift,natecook1000/swift,tinysun212/swift-windows,tinysun212/swift-windows,danielmartin/swift,LeoShimonaka/swift,practicalswift/swift,kstaring/swift,parkera/swift,deyton/swift,harlanhaskins/swift,russbishop/swift,danielmartin/swift,gribozavr/swift,khizkhiz/swift,return/swift,gmilos/swift,Ivacker/swift,OscarSwanros/swift,jckarter/swift,practicalswift/swift,hooman/swift,kperryua/swift,brentdax/swift,codestergit/swift,stephentyrone/swift,LeoShimonaka/swift,ken0nek/swift,jopamer/swift,harlanhaskins/swift,MukeshKumarS/Swift,tardieu/swift,nathawes/swift,parkera/swift,Jnosh/swift,hooman/swift,gribozavr/swift,gottesmm/swift,sdulal/swift,KrishMunot/swift,benlangmuir/swift,shajrawi/swift,allevato/swift,emilstahl/swift,swiftix/swift.old,roambotics/swift,mightydeveloper/swift,xwu/swift,ben-ng/swift,jopamer/swift,tinysun212/swift-windows,jckarter/swift,swiftix/swift.old,glessard/swift,huonw/swift,airspeedswift/swift,lorentey/swift,slavapestov/swift,russbishop/swift,harlanhaskins/swift,benlangmuir/swift,JGiola/swift,huonw/swift,jckarter/swift,devincoughlin/swift,atrick/swift,zisko/swift,kentya6/swift,uasys/swift,gribozavr/swift,airspeedswift/swift,return/swift,Jnosh/swift,JaSpa/swift,harlanhaskins/swift,bitjammer/swift,aschwaighofer/swift,jopamer/swift,jmgc/swift,danielmartin/swift,sschiau/swift,OscarSwanros/swift,arvedviehweger/swift,bitjammer/swift,lorentey/swift,JGiola/swift,tjw/swift,rudkx/swift,manavgabhawala/swift,LeoShimonaka/swift,manavgabhawala/swift,huonw/swift,cbrentharris/swift,airspeedswift/swift,allevato/swift,apple/swift,apple/swift,xedin/swift,devincoughlin/swift,jmgc/swift,natecook1000/swift,jtbandes/swift,dduan/swift,emilstahl/swift,jmgc/swift,nathawes/swift,felix91gr/swift,brentdax/swift,jopamer/swift,xedin/swift,uasys/swift,benlangmuir/swift,mightydeveloper/swift,tkremenek/swift,gmilos/swift,kperryua/swift,devincoughlin/swift,gottesmm/swift,sschiau/swift,JGiola/swift,cbrentharris/swift,tjw/swift,frootloops/swift,zisko/swift,shahmishal/swift,aschwaighofer/swift,tinysun212/swift-windows,kusl/swift,shahmishal/swift,ahoppen/swift,IngmarStein/swift,kstaring/swift,austinzheng/swift,apple/swift,Ivacker/swift,shajrawi/swift,jckarter/swift,kentya6/swift,felix91gr/swift,Ivacker/swift,swiftix/swift,natecook1000/swift,alblue/swift,tkremenek/swift,kstaring/swift,gmilos/swift,djwbrown/swift,gregomni/swift,ben-ng/swift,OscarSwanros/swift,JaSpa/swift,arvedviehweger/swift,shajrawi/swift,codestergit/swift,Jnosh/swift,ken0nek/swift,MukeshKumarS/Swift,kperryua/swift,shahmishal/swift,adrfer/swift,amraboelela/swift,kentya6/swift,mightydeveloper/swift,harlanhaskins/swift,uasys/swift,jckarter/swift,shahmishal/swift,swiftix/swift.old,arvedviehweger/swift,CodaFi/swift,kentya6/swift,tkremenek/swift,danielmartin/swift,tinysun212/swift-windows,danielmartin/swift,xedin/swift,therealbnut/swift,austinzheng/swift,hooman/swift,gottesmm/swift,KrishMunot/swift,Jnosh/swift,sdulal/swift,JaSpa/swift,CodaFi/swift,swiftix/swift.old,alblue/swift,xedin/swift,jtbandes/swift,kentya6/swift,brentdax/swift,harlanhaskins/swift,benlangmuir/swift,calebd/swift,dduan/swift,return/swift,tinysun212/swift-windows,stephentyrone/swift,karwa/swift,roambotics/swift,codestergit/swift,calebd/swift,gmilos/swift,milseman/swift,modocache/swift,bitjammer/swift,rudkx/swift,khizkhiz/swift,adrfer/swift,return/swift,tinysun212/swift-windows,tjw/swift,dduan/swift,amraboelela/swift,mightydeveloper/swift,emilstahl/swift,airspeedswift/swift,dduan/swift,danielmartin/swift,austinzheng/swift,austinzheng/swift,hughbe/swift,hughbe/swift,Jnosh/swift,djwbrown/swift,kusl/swift,dduan/swift,xwu/swift,emilstahl/swift,zisko/swift,IngmarStein/swift,modocache/swift,hooman/swift,therealbnut/swift,frootloops/swift,JaSpa/swift,shajrawi/swift,deyton/swift,sdulal/swift,zisko/swift,gribozavr/swift,airspeedswift/swift,practicalswift/swift,djwbrown/swift,natecook1000/swift,gmilos/swift,codestergit/swift,arvedviehweger/swift,russbishop/swift,milseman/swift,ben-ng/swift,MukeshKumarS/Swift,milseman/swift,allevato/swift,Jnosh/swift,huonw/swift,zisko/swift,natecook1000/swift,airspeedswift/swift,shajrawi/swift,stephentyrone/swift,amraboelela/swift,nathawes/swift,return/swift,codestergit/swift,brentdax/swift,austinzheng/swift,felix91gr/swift,aschwaighofer/swift,tjw/swift,therealbnut/swift,xedin/swift,karwa/swift,glessard/swift,gribozavr/swift,deyton/swift,lorentey/swift,modocache/swift,sschiau/swift,russbishop/swift,karwa/swift,mightydeveloper/swift,swiftix/swift,ben-ng/swift,rudkx/swift,alblue/swift,shahmishal/swift,IngmarStein/swift,SwiftAndroid/swift,ahoppen/swift,kstaring/swift,cbrentharris/swift,slavapestov/swift,sdulal/swift,dduan/swift,calebd/swift,sschiau/swift