[Code completion] Suppress vacuous infix operator completions.
[Code completion] Suppress vacuous infix operator completions.

With the previous type-checker change, we end up with some vacuous
infix operator completions, where the right-hand side and result type
are *both* type variables. Suppress these; they aren't useful to the
developer.

JaSpa/swift,therealbnut/swift,allevato/swift,Jnosh/swift,calebd/swift,hooman/swift,deyton/swift,natecook1000/swift,jtbandes/swift,huonw/swift,codestergit/swift,brentdax/swift,deyton/swift,swiftix/swift,apple/swift,xwu/swift,practicalswift/swift,calebd/swift,arvedviehweger/swift,jckarter/swift,aschwaighofer/swift,zisko/swift,djwbrown/swift,alblue/swift,OscarSwanros/swift,manavgabhawala/swift,Jnosh/swift,djwbrown/swift,huonw/swift,parkera/swift,modocache/swift,kstaring/swift,lorentey/swift,CodaFi/swift,hooman/swift,manavgabhawala/swift,gottesmm/swift,lorentey/swift,tjw/swift,shahmishal/swift,uasys/swift,manavgabhawala/swift,danielmartin/swift,kstaring/swift,return/swift,felix91gr/swift,JGiola/swift,practicalswift/swift,apple/swift,hooman/swift,tjw/swift,kstaring/swift,jopamer/swift,parkera/swift,gribozavr/swift,aschwaighofer/swift,JaSpa/swift,ben-ng/swift,jopamer/swift,shajrawi/swift,alblue/swift,jmgc/swift,sschiau/swift,felix91gr/swift,harlanhaskins/swift,hooman/swift,tardieu/swift,manavgabhawala/swift,parkera/swift,kperryua/swift,gribozavr/swift,glessard/swift,huonw/swift,tinysun212/swift-windows,bitjammer/swift,airspeedswift/swift,jmgc/swift,JaSpa/swift,amraboelela/swift,JaSpa/swift,hughbe/swift,hughbe/swift,airspeedswift/swift,gottesmm/swift,alblue/swift,arvedviehweger/swift,devincoughlin/swift,deyton/swift,manavgabhawala/swift,gmilos/swift,stephentyrone/swift,gottesmm/swift,danielmartin/swift,devincoughlin/swift,gregomni/swift,karwa/swift,aschwaighofer/swift,karwa/swift,natecook1000/swift,kperryua/swift,atrick/swift,ahoppen/swift,arvedviehweger/swift,JGiola/swift,kperryua/swift,OscarSwanros/swift,amraboelela/swift,roambotics/swift,gregomni/swift,uasys/swift,zisko/swift,OscarSwanros/swift,tardieu/swift,nathawes/swift,roambotics/swift,bitjammer/swift,gmilos/swift,amraboelela/swift,modocache/swift,allevato/swift,milseman/swift,devincoughlin/swift,uasys/swift,bitjammer/swift,frootloops/swift,benlangmuir/swift,stephentyrone/swift,CodaFi/swift,gottesmm/swift,OscarSwanros/swift,sschiau/swift,shahmishal/swift,shahmishal/swift,modocache/swift,sschiau/swift,tjw/swift,glessard/swift,calebd/swift,jtbandes/swift,practicalswift/swift,lorentey/swift,gribozavr/swift,atrick/swift,nathawes/swift,karwa/swift,sschiau/swift,milseman/swift,xwu/swift,bitjammer/swift,rudkx/swift,ben-ng/swift,austinzheng/swift,glessard/swift,hughbe/swift,parkera/swift,Jnosh/swift,natecook1000/swift,parkera/swift,xedin/swift,deyton/swift,codestergit/swift,devincoughlin/swift,JGiola/swift,ben-ng/swift,jmgc/swift,codestergit/swift,huonw/swift,jckarter/swift,tkremenek/swift,uasys/swift,return/swift,natecook1000/swift,calebd/swift,arvedviehweger/swift,devincoughlin/swift,milseman/swift,austinzheng/swift,xwu/swift,stephentyrone/swift,felix91gr/swift,aschwaighofer/swift,hughbe/swift,tkremenek/swift,manavgabhawala/swift,deyton/swift,ben-ng/swift,hughbe/swift,practicalswift/swift,danielmartin/swift,devincoughlin/swift,allevato/swift,shajrawi/swift,natecook1000/swift,kperryua/swift,kstaring/swift,hooman/swift,CodaFi/swift,gmilos/swift,arvedviehweger/swift,sschiau/swift,return/swift,ahoppen/swift,jtbandes/swift,therealbnut/swift,hughbe/swift,brentdax/swift,modocache/swift,uasys/swift,benlangmuir/swift,gregomni/swift,tinysun212/swift-windows,therealbnut/swift,gmilos/swift,jopamer/swift,ahoppen/swift,xedin/swift,deyton/swift,sschiau/swift,airspeedswift/swift,CodaFi/swift,glessard/swift,shahmishal/swift,shajrawi/swift,sschiau/swift,zisko/swift,xwu/swift,therealbnut/swift,milseman/swift,gmilos/swift,felix91gr/swift,allevato/swift,apple/swift,practicalswift/swift,roambotics/swift,benlangmuir/swift,gmilos/swift,harlanhaskins/swift,karwa/swift,jmgc/swift,bitjammer/swift,shahmishal/swift,codestergit/swift,austinzheng/swift,milseman/swift,apple/swift,Jnosh/swift,hooman/swift,xedin/swift,swiftix/swift,shahmishal/swift,frootloops/swift,harlanhaskins/swift,djwbrown/swift,tkremenek/swift,glessard/swift,jmgc/swift,austinzheng/swift,airspeedswift/swift,nathawes/swift,tardieu/swift,gottesmm/swift,manavgabhawala/swift,OscarSwanros/swift,practicalswift/swift,tinysun212/swift-windows,hooman/swift,benlangmuir/swift,austinzheng/swift,return/swift,calebd/swift,CodaFi/swift,gribozavr/swift,lorentey/swift,allevato/swift,kstaring/swift,codestergit/swift,tjw/swift,amraboelela/swift,ben-ng/swift,tardieu/swift,apple/swift,brentdax/swift,lorentey/swift,shahmishal/swift,amraboelela/swift,parkera/swift,natecook1000/swift,roambotics/swift,austinzheng/swift,tjw/swift,xedin/swift,uasys/swift,alblue/swift,brentdax/swift,djwbrown/swift,lorentey/swift,jopamer/swift,calebd/swift,atrick/swift,stephentyrone/swift,allevato/swift,atrick/swift,codestergit/swift,tinysun212/swift-windows,therealbnut/swift,benlangmuir/swift,swiftix/swift,JaSpa/swift,harlanhaskins/swift,amraboelela/swift,tardieu/swift,tkremenek/swift,JaSpa/swift,frootloops/swift,austinzheng/swift,calebd/swift,hughbe/swift,lorentey/swift,harlanhaskins/swift,zisko/swift,swiftix/swift,ben-ng/swift,kperryua/swift,jckarter/swift,parkera/swift,jopamer/swift,shajrawi/swift,shajrawi/swift,gregomni/swift,parkera/swift,JGiola/swift,swiftix/swift,JGiola/swift,frootloops/swift,rudkx/swift,aschwaighofer/swift,nathawes/swift,danielmartin/swift,zisko/swift,airspeedswift/swift,xwu/swift,xedin/swift,gribozavr/swift,rudkx/swift,stephentyrone/swift,huonw/swift,glessard/swift,jtbandes/swift,huonw/swift,arvedviehweger/swift,gottesmm/swift,xwu/swift,ahoppen/swift,shajrawi/swift,shajrawi/swift,jckarter/swift,jtbandes/swift,swiftix/swift,aschwaighofer/swift,danielmartin/swift,uasys/swift,tkremenek/swift,swiftix/swift,OscarSwanros/swift,brentdax/swift,therealbnut/swift,nathawes/swift,harlanhaskins/swift,atrick/swift,jopamer/swift,tkremenek/swift,xedin/swift,karwa/swift,tardieu/swift,danielmartin/swift,djwbrown/swift,bitjammer/swift,frootloops/swift,huonw/swift,gmilos/swift,modocache/swift,airspeedswift/swift,tkremenek/swift,gribozavr/swift,jtbandes/swift,practicalswift/swift,devincoughlin/swift,benlangmuir/swift,shahmishal/swift,lorentey/swift,tjw/swift,return/swift,tinysun212/swift-windows,milseman/swift,natecook1000/swift,xedin/swift,deyton/swift,milseman/swift,shajrawi/swift,amraboelela/swift,frootloops/swift,gregomni/swift,aschwaighofer/swift,karwa/swift,tardieu/swift,xwu/swift,jopamer/swift,practicalswift/swift,devincoughlin/swift,nathawes/swift,kstaring/swift,gottesmm/swift,zisko/swift,roambotics/swift,arvedviehweger/swift,return/swift,modocache/swift,rudkx/swift,kstaring/swift,jtbandes/swift,allevato/swift,alblue/swift,jckarter/swift,stephentyrone/swift,therealbnut/swift,nathawes/swift,JaSpa/swift,tinysun212/swift-windows,karwa/swift,rudkx/swift,zisko/swift,frootloops/swift,atrick/swift,stephentyrone/swift,xedin/swift,rudkx/swift,felix91gr/swift,codestergit/swift,jmgc/swift,CodaFi/swift,ahoppen/swift,return/swift,bitjammer/swift,djwbrown/swift,felix91gr/swift,tjw/swift,harlanhaskins/swift,Jnosh/swift,roambotics/swift,CodaFi/swift,alblue/swift,brentdax/swift,jmgc/swift,sschiau/swift,gribozavr/swift,jckarter/swift,gribozavr/swift,modocache/swift,ahoppen/swift,jckarter/swift,JGiola/swift,ben-ng/swift,airspeedswift/swift,OscarSwanros/swift,apple/swift,Jnosh/swift,felix91gr/swift,Jnosh/swift,tinysun212/swift-windows,gregomni/swift,karwa/swift,alblue/swift,kperryua/swift,djwbrown/swift,danielmartin/swift,kperryua/swift,brentdax/swift