[SILGen] Minor improvements to generateEnumCaseBlocks
[SILGen] Minor improvements to generateEnumCaseBlocks

Noticed by MichaelG while reviewing my changes in the previous commit.
No intended functionality change.

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