[ClangImporter] Simplify handling of BOOL/Boolean slightly
[ClangImporter] Simplify handling of BOOL/Boolean slightly

At least as far as ImportHint was concerned, these two mapped types
were being treated the same.

No functionality change.

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