(Stash) Add SILVerifier rule to prevent conflicting arg DIVariable
(Stash) Add SILVerifier rule to prevent conflicting arg DIVariable

This rule tries to prevent two DIVariables -- with different types --
conflicting with each other on the same argument number.
If this rule fails, it's highly possible that we forgot to add
'inlinedAt' somewhere.

roambotics/swift,ahoppen/swift,benlangmuir/swift,apple/swift,gregomni/swift,roambotics/swift,benlangmuir/swift,ahoppen/swift,JGiola/swift,ahoppen/swift,ahoppen/swift,rudkx/swift,atrick/swift,benlangmuir/swift,apple/swift,gregomni/swift,gregomni/swift,atrick/swift,rudkx/swift,JGiola/swift,xwu/swift,ahoppen/swift,xwu/swift,rudkx/swift,roambotics/swift,glessard/swift,glessard/swift,glessard/swift,xwu/swift,apple/swift,atrick/swift,JGiola/swift,gregomni/swift,roambotics/swift,gregomni/swift,gregomni/swift,JGiola/swift,xwu/swift,apple/swift,apple/swift,rudkx/swift,benlangmuir/swift,benlangmuir/swift,apple/swift,xwu/swift,atrick/swift,JGiola/swift,xwu/swift,xwu/swift,ahoppen/swift,glessard/swift,rudkx/swift,glessard/swift,glessard/swift,rudkx/swift,JGiola/swift,atrick/swift,atrick/swift,roambotics/swift,roambotics/swift,benlangmuir/swift