[ownership] Refactor out def-use compatibility checking out of gatherUsers() into a helper method.
[ownership] Refactor out def-use compatibility checking out of gatherUsers() into a helper method.

This together with Operand::isConsumingUse() allows me to completely hide
OperandOwnershipKindMap from the main flow of the algorithm which makes it
easier to understand.

airspeedswift/swift,rudkx/swift,ahoppen/swift,ahoppen/swift,aschwaighofer/swift,stephentyrone/swift,stephentyrone/swift,hooman/swift,roambotics/swift,jmgc/swift,harlanhaskins/swift,xwu/swift,CodaFi/swift,allevato/swift,hooman/swift,xwu/swift,apple/swift,xwu/swift,gregomni/swift,gregomni/swift,glessard/swift,JGiola/swift,nathawes/swift,atrick/swift,tkremenek/swift,JGiola/swift,gregomni/swift,airspeedswift/swift,aschwaighofer/swift,jckarter/swift,apple/swift,roambotics/swift,jckarter/swift,apple/swift,tkremenek/swift,tkremenek/swift,benlangmuir/swift,hooman/swift,aschwaighofer/swift,stephentyrone/swift,stephentyrone/swift,glessard/swift,aschwaighofer/swift,xwu/swift,parkera/swift,harlanhaskins/swift,allevato/swift,jckarter/swift,jmgc/swift,stephentyrone/swift,allevato/swift,xwu/swift,ahoppen/swift,airspeedswift/swift,roambotics/swift,jmgc/swift,harlanhaskins/swift,airspeedswift/swift,glessard/swift,apple/swift,nathawes/swift,aschwaighofer/swift,JGiola/swift,parkera/swift,parkera/swift,hooman/swift,tkremenek/swift,hooman/swift,CodaFi/swift,tkremenek/swift,atrick/swift,hooman/swift,atrick/swift,aschwaighofer/swift,xwu/swift,stephentyrone/swift,gregomni/swift,CodaFi/swift,atrick/swift,gregomni/swift,glessard/swift,tkremenek/swift,aschwaighofer/swift,parkera/swift,benlangmuir/swift,apple/swift,airspeedswift/swift,roambotics/swift,JGiola/swift,glessard/swift,rudkx/swift,nathawes/swift,rudkx/swift,nathawes/swift,nathawes/swift,ahoppen/swift,parkera/swift,harlanhaskins/swift,glessard/swift,ahoppen/swift,airspeedswift/swift,CodaFi/swift,CodaFi/swift,harlanhaskins/swift,benlangmuir/swift,tkremenek/swift,gregomni/swift,ahoppen/swift,parkera/swift,nathawes/swift,jmgc/swift,harlanhaskins/swift,CodaFi/swift,atrick/swift,JGiola/swift,harlanhaskins/swift,rudkx/swift,benlangmuir/swift,parkera/swift,jckarter/swift,allevato/swift,jmgc/swift,xwu/swift,allevato/swift,stephentyrone/swift,jckarter/swift,JGiola/swift,allevato/swift,rudkx/swift,jmgc/swift,airspeedswift/swift,CodaFi/swift,hooman/swift,nathawes/swift,jckarter/swift,rudkx/swift,apple/swift,parkera/swift,jckarter/swift,benlangmuir/swift,atrick/swift,roambotics/swift,roambotics/swift,benlangmuir/swift,allevato/swift,jmgc/swift