[AST] Use ProtocolDecl::createGenericParamsIfMissing() where appropriate.
[AST] Use ProtocolDecl::createGenericParamsIfMissing() where appropriate.

Thanks to @slavapestov for noticing that I hard-coded this, badly.

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