[NFC] readable control flow in lexImpl default case
[NFC] readable control flow in lexImpl default case

There are 3 token flow and 2 trivia flow.
This commit makes it clear and more readable.

And apply clang-format.

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