Runtime: Do the bare minimum balancing for bridge casting at +0.
Runtime: Do the bare minimum balancing for bridge casting at +0.

The logic here is causing leaks in some situations, and it's likely we'll want
bridging calls to go back to +1 again anyway, so do the minimum adaptation to
the +0 convention for now.

rdar://34222540

rudkx/swift,tjw/swift,harlanhaskins/swift,tjw/swift,shahmishal/swift,shajrawi/swift,gribozavr/swift,jopamer/swift,stephentyrone/swift,brentdax/swift,apple/swift,devincoughlin/swift,airspeedswift/swift,danielmartin/swift,gregomni/swift,tkremenek/swift,nathawes/swift,benlangmuir/swift,brentdax/swift,karwa/swift,danielmartin/swift,austinzheng/swift,benlangmuir/swift,amraboelela/swift,tkremenek/swift,stephentyrone/swift,alblue/swift,CodaFi/swift,huonw/swift,stephentyrone/swift,allevato/swift,aschwaighofer/swift,nathawes/swift,sschiau/swift,xwu/swift,JGiola/swift,parkera/swift,lorentey/swift,devincoughlin/swift,alblue/swift,gregomni/swift,ahoppen/swift,gribozavr/swift,shahmishal/swift,tkremenek/swift,practicalswift/swift,xwu/swift,glessard/swift,practicalswift/swift,austinzheng/swift,jckarter/swift,practicalswift/swift,atrick/swift,karwa/swift,benlangmuir/swift,practicalswift/swift,harlanhaskins/swift,nathawes/swift,amraboelela/swift,CodaFi/swift,karwa/swift,xwu/swift,airspeedswift/swift,lorentey/swift,karwa/swift,rudkx/swift,glessard/swift,jmgc/swift,devincoughlin/swift,airspeedswift/swift,hooman/swift,benlangmuir/swift,tjw/swift,karwa/swift,nathawes/swift,huonw/swift,parkera/swift,tkremenek/swift,shahmishal/swift,CodaFi/swift,jmgc/swift,rudkx/swift,natecook1000/swift,parkera/swift,roambotics/swift,roambotics/swift,alblue/swift,airspeedswift/swift,karwa/swift,ahoppen/swift,huonw/swift,lorentey/swift,harlanhaskins/swift,allevato/swift,natecook1000/swift,jopamer/swift,danielmartin/swift,apple/swift,glessard/swift,nathawes/swift,jopamer/swift,jckarter/swift,apple/swift,roambotics/swift,amraboelela/swift,sschiau/swift,tjw/swift,CodaFi/swift,jmgc/swift,xwu/swift,aschwaighofer/swift,benlangmuir/swift,airspeedswift/swift,tkremenek/swift,CodaFi/swift,JGiola/swift,sschiau/swift,lorentey/swift,atrick/swift,natecook1000/swift,glessard/swift,gribozavr/swift,practicalswift/swift,gribozavr/swift,atrick/swift,devincoughlin/swift,hooman/swift,parkera/swift,jopamer/swift,gregomni/swift,brentdax/swift,CodaFi/swift,practicalswift/swift,JGiola/swift,ahoppen/swift,natecook1000/swift,danielmartin/swift,allevato/swift,shajrawi/swift,lorentey/swift,shajrawi/swift,allevato/swift,glessard/swift,shahmishal/swift,jopamer/swift,sschiau/swift,devincoughlin/swift,stephentyrone/swift,rudkx/swift,alblue/swift,glessard/swift,shajrawi/swift,jopamer/swift,atrick/swift,amraboelela/swift,gregomni/swift,alblue/swift,hooman/swift,stephentyrone/swift,stephentyrone/swift,hooman/swift,xwu/swift,jmgc/swift,shahmishal/swift,apple/swift,jopamer/swift,shajrawi/swift,xwu/swift,jckarter/swift,karwa/swift,roambotics/swift,allevato/swift,sschiau/swift,gregomni/swift,gribozavr/swift,huonw/swift,aschwaighofer/swift,huonw/swift,airspeedswift/swift,jckarter/swift,ahoppen/swift,jmgc/swift,devincoughlin/swift,tkremenek/swift,danielmartin/swift,JGiola/swift,huonw/swift,shajrawi/swift,harlanhaskins/swift,benlangmuir/swift,ahoppen/swift,gregomni/swift,xedin/swift,nathawes/swift,ahoppen/swift,jmgc/swift,xedin/swift,amraboelela/swift,austinzheng/swift,shahmishal/swift,rudkx/swift,xedin/swift,tjw/swift,lorentey/swift,amraboelela/swift,nathawes/swift,karwa/swift,austinzheng/swift,allevato/swift,xedin/swift,sschiau/swift,natecook1000/swift,danielmartin/swift,airspeedswift/swift,sschiau/swift,parkera/swift,gribozavr/swift,austinzheng/swift,alblue/swift,jckarter/swift,devincoughlin/swift,stephentyrone/swift,huonw/swift,apple/swift,practicalswift/swift,atrick/swift,harlanhaskins/swift,xedin/swift,xedin/swift,harlanhaskins/swift,devincoughlin/swift,alblue/swift,practicalswift/swift,shahmishal/swift,atrick/swift,tkremenek/swift,xwu/swift,jckarter/swift,roambotics/swift,gribozavr/swift,brentdax/swift,rudkx/swift,xedin/swift,amraboelela/swift,shajrawi/swift,allevato/swift,brentdax/swift,austinzheng/swift,xedin/swift,aschwaighofer/swift,parkera/swift,jckarter/swift,danielmartin/swift,shajrawi/swift,harlanhaskins/swift,jmgc/swift,aschwaighofer/swift,lorentey/swift,parkera/swift,brentdax/swift,brentdax/swift,sschiau/swift,lorentey/swift,roambotics/swift,JGiola/swift,natecook1000/swift,hooman/swift,gribozavr/swift,austinzheng/swift,aschwaighofer/swift,hooman/swift,apple/swift,parkera/swift,tjw/swift,JGiola/swift,tjw/swift,aschwaighofer/swift,shahmishal/swift,CodaFi/swift,natecook1000/swift,hooman/swift