Add test cases for more permutations.
Add test cases for more permutations.

Make sure that we still emit warnings even if the let bindings are in
different positions.

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