[SILGen] Remove incomplete support for generic bridging functions in getBridgingFn
[SILGen] Remove incomplete support for generic bridging functions in getBridgingFn

getBridgingFn was implementing some incomplete support for generic
bridging functions, but it was not used anyway.

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