Fix ExecutionEngine include
Fix ExecutionEngine include

LLVM Commit 662c55442f17c changed the name of the header file, causing
some breakage.

roambotics/swift,ahoppen/swift,apple/swift,benlangmuir/swift,ahoppen/swift,atrick/swift,rudkx/swift,gregomni/swift,apple/swift,gregomni/swift,JGiola/swift,ahoppen/swift,rudkx/swift,atrick/swift,gregomni/swift,roambotics/swift,benlangmuir/swift,gregomni/swift,glessard/swift,gregomni/swift,glessard/swift,rudkx/swift,JGiola/swift,benlangmuir/swift,atrick/swift,apple/swift,rudkx/swift,gregomni/swift,ahoppen/swift,apple/swift,atrick/swift,rudkx/swift,rudkx/swift,benlangmuir/swift,roambotics/swift,JGiola/swift,roambotics/swift,glessard/swift,JGiola/swift,JGiola/swift,apple/swift,apple/swift,ahoppen/swift,glessard/swift,roambotics/swift,benlangmuir/swift,ahoppen/swift,benlangmuir/swift,JGiola/swift,atrick/swift,roambotics/swift,glessard/swift,atrick/swift,glessard/swift