IRGen: Try to fix failure on arm64e on test/IRGen/generic_vtable.swift
IRGen: Try to fix failure on arm64e on test/IRGen/generic_vtable.swift

rdar://86577465

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