Directly include ErrorOr.h and MemoryBuffer.h to make Passes.cpp resilient against potential forward declarations.
Directly include ErrorOr.h and MemoryBuffer.h to make Passes.cpp resilient against potential forward declarations.

In the swift-602-branch, these are forward declared in one of the
headers included in this file yielded a compilation error. Rather than
just fixing the compilation failure on that branch, this commit makes
the entire file more redundent since who knows in the future these two
types may be forward declared again.

Swift SVN r24066

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