[ModuleInterfaces] Add adjacent swiftmodule to dependencies
[ModuleInterfaces] Add adjacent swiftmodule to dependencies

If there’s a `.swiftmodule` corresponding to the `.swiftinterface` we’re loading, but it’s out of date or otherwise unusable, still make it a dependency of the cached module.

The general assumption with cached modules is that, by virtue of them being in the cache, they have a more up-to-date view of the world than the adjacent compiled module. However, if a new `.swiftmodule` comes along that’s totally valid, we should consider it as having a newer view of the world than the cached one, so we should use it instead.

Fixes rdar://51959788

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