[Runtime] Remove duplicate witness checking for now.
[Runtime] Remove duplicate witness checking for now.

It's breaking on SwiftPM, so remove it for now and follow-up to
investigate with rdar://problem/44627274.

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